Intro To Quantum Mechanics
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Student Life

# Intro To Quantum Mechanics

## It's not exactly rocket science, folks.

27
Gloria Sun

Hello hello! I’m a first-year at Wellesley College, an all-women’s liberal arts college in Massachusetts. I’m teaching a series of crash courses on Chemistry – you can find the page here. Without further ado, let’s dive into the world of quantum mechanics – no previous experience necessary, but it gets intense, so follow along!

(Bear in mind that you do not need to understand everything in this tutorial.)

#### WHAT IS A WAVE?

Think of ripples in a pool, or sound produced by the radio. Waves are periodic disturbances/oscillations that pass through a medium (i.e. air, water, etc.).

A cycle is the repeating unit of a wave. Multiple cycles make up a continuous wave.

The main equation we use to measure waves is v = λf. Think about it, it’s just the velocity equation “v = d/t” in disguise. The velocity of a wave is v. The symbol λ (pronounced lambda) is the wavelength, which is just a distance (d). And f is the frequency is the amount of time it takes for a cycle to travel the distance of that wavelength, so it’s just time (t).

Of course, we can substitute the speed of light constant, c = 3×108 ms-2 into the equation above so that we can calculate the wavelength or frequency of an electromagnetic wave, which travels specifically at that velocity in a vacuum. This allows us to transition nicely into our next section.

#### ELECTROMAGNETIC WAVES

What exactly is electromagnetic radiation? If we break apart the word, we see “electric” and “magnetic”. We see two perpendicular fields – an electric field and a magnetic field – that propagate one another.

Of course, what we really can see of electromagnetic radiation, is visible light. That’s only a tiny portion of the spectrum though, other examples of EM radiation include ultraviolet light, infrared rays, X-rays, and radio waves, and they all have different applications in our lives.

#### SPECTROSCOPY

Spectroscopy is a way of studying absorptions and emissions of electromagnetic radiation by matter. All kinds of spectra result from transitions between the ground state and the excited state.

As you may know, electrons exist in different orbitals around the atom. Some of these orbitals are at a lower energy state. When an electron moves from an orbital of a higher energy to one of lower energy level, it will emit a packet of energy called a photon. When an electron jumps to a higher energy level, it absorbs a photon.

Essentially what these diagrams represent are the wavelengths of the photons absorbed and emitted for a specific element, since the transitions are “quantized” and only occur for specific wavelengths. This serves as a sort of “bar code” to allow scientists to identify what elements are in a sample.

### QUANTUM THEORY OF RADIATION

#### THE DUAL NATURE OF RADIATION

Light was previously known to exhibit wave properties, such as interference and diffraction. However, a century or so ago, it was observed that light could also behave as a particle (i.e. a photon).

The energy carried by these photons is proportional to the frequency of the light: E = hf, where h is Planck’s constant: h = 6.6261×10-34 J-1.

We have to accept the wave-particle duality of electromagnetic radiation!

#### PHOTOELECTRIC EFFECT

The process by which electrons are ejected from a metal surface when light strikes the surface is called the photoelectric effect. The kinetic energy of the ejected electron is observed to be independent of the intensity of radiation, and the photoelectric effect is completely absent below a certain threshold frequency. These phenomena couldn’t be explained by classical physics, and Einstein won a Nobel Prize for his explanation:

0.5mv2 = hf – φ

The left side is the electron’s kinetic energy, which is greater than or equal to 0.

hf is the energy of the photon (E = hf), and φ is the work function – the minimum energy required to remove an electron from the surface (specific to the metal in question).

At the threshold frequency the kinetic energy of the electrons is 0. Below that, no electrons are ejected. The threshold frequency can be given by this equation:

hf = φ

#### MATTER WAVES: DUAL NATURE OF MATTER

Louis de Broglie proposed if light has wave-particle duality, then matter, which is supposedly a particle, may also have wave-like properties.

Given the definition of momentum (p = mv), a particle with mass m and speed v should have a wavelength:

λ = h/p = h/mv

Quantum effects are unobservable for macroscopic objects (technically, you have a de Broglie wavelength!), but for a microscopic object, we obtain a wavelength of atomic dimensions. Electrons show interference patterns characteristic of waves (i.e. diffraction).

#### HEISENBERG’S UNCERTAINTY PRINCIPLE

According to Heisenberg’s uncertainty principle, it is impossible to make simultaneous and exact measurements of both the position (x) and momentum (p) of a particle.

(Δx)(Δp) ≈ h

So, if Δx is small, then Δp will be large, and vice versa. The more precisely the position is known, the greater the uncertainty in momentum. The uncertainty is inherent and cannot be reduced by improvement in measurement technique.

Since it’s not possible to specify the trajectory of microscopic particles such as electrons, the Bohr model of the atom (the one you learned in school, with the orbits of electrons around the nucleus) is incompatible with this understanding.

#### WAVE MECHANICS AND SCHRÖDINGER’S EQUATION

If you’re confused at this point, don’t worry! Richard Feynman himself once said, “I don’t understand it. Nobody does.” You’re normal.

Each state of a particle is associated with a wavefunction. Given the wavefunction corresponding to a particular state, one can calculate the probability of finding the particle in any specified region of space.

To get the wavefunction, we need to solve Schrödinger’s equation. This is the central equation of quantum mechanics.

HΨ = EΨ

H is the Hamiltonian operator, Ψ is the wavefunction and E is the energy. That’s all you need to know for now.

(Solving the equation is super, super, super complicated. So let’s just go ahead and discuss the solutions to the Schrödinger equation.)

Solving the equation (let’s say we did) yields a series of wavefunctions and energies. (Actually, the hydrogen atom can be exactly solved. All the other elements have approximate solutions.)

1. The wavefunction (orbital) gives information about the position of an electron.
2. The quantized energy levels are useful in understanding line spectra.

#### FOUR QUANTUM NUMBERS

There are four quantum numbers needed to specify the state of an electron in an atom, which we will discuss next.

1. Principal Quantum Number
Symbol: n
Permitted values: 1,2,3,4…any positive integral value starting with 1
n determines the size of an orbital and the distance of the electron from the nucleus. n=1 corresponds to the orbital closest to the nucleus, and is the lowest energy orbital.
The energy for an electron is given by ; where k for H is 2.179×10^-18 J.
Because of the n^2 in the denominator, the spacing between successive orbitals decreases with increasing n.
An electron falling from a higher n level will emit a photon, which will have the same energy as the energy difference between the electron’s initial and final states. This can be represented by the Bohr-Einstein relationship:
To get the frequency of the emitted light, we can use the Rydberg formula:
2. Orbital Angular-Momentum Quantum Number
Symbol: l
Permitted values: 0,1,2…n-1
The quantum number l determines the shape of the orbital. The letter symbols for l are used for orbital designation so that s (l=0), p (l=1), d (l=2), f (l=3), and g (l=4). For example, the s orbitals are all spherical in shape while the p orbital has a dumbbell shape.
3. Magnetic Quantum Number
Symbol: ml
Permitted values: –l, –l+1, –l+2…0,…l-2, l-1, l; all integral values between -l and +l including 0
The magnetic quantum number determines the orientation of the orbital and the behavior of electrons in a magnetic field. For example, there are 3 degenerate 2p atomic orbitals that split into three different energy levels, which correspond to the three different values of the magnetic quantum numbers for l=1.
4. Spin Quantum Number
Symbol: ms
Permitted values: -1/2, +1/2
In the Stern-Gerlach experiment, it was shown that a beam of atoms would be split in a magnetic field. The direction in which the electrons move is based on the spin of an electron, and can’t really be explained via classical mechanics.

#### PHYSICAL MEANING OF WAVEFUNCTIONS

Orbitals are regions in which electrons are the most likely to be found. The wavefunction Ψ is a set of numbers, in which one particular value is assigned to every point in space.

Let’s look at an example. The wavefunctions for H are the s, p, d, and f orbitals, and the 1s orbital is an exponential decay function (no need for memorization, just observe):

where a0 is a constant called the Bohr radius and r is the distance of the electron from the nucleus.

The 1s wavefunction only depends on r, but with other wavefunctions the variables can also depend on θ (latitude) and φ (longitude). We express the wavefunction in spherical polar coordinates instead of Cartesian, so we can go out from the nucleus a distance r to a specific θ and φ on the sphere to compute the value of ψ at that point (a plain number with a sign).

Another example with the hydrogen atom is the 2px orbital (don’t sweat it!):

We can separate this wavefunction into two components – the radial function depends on r, while the angular function depends on θ and φ.

The general expression for the hydrogen atom wavefunction is as follows:

and depends on the three quantum numbers (n, l, ml), and three coordinates (r,θ,φ). The hydrogen atom has an infinite number of orbitals even though only the lowest energy 1s orbital is occupied in the ground state of the atom.

#### BORN’S INTERPRETATION OF ORBITALS

So we know now that Bohr’s model doesn’t really work with what we know. Schrödinger describes electrons through orbitals in his mechanical model. Max Born further sought symmetry between light and matter when trying to interpret the wavefunction.

Born proposed that the probability of finding an electron at a point is equal to the square of the wavefunction at that point – the quantity ψ2 is called the probability density/electron density.

For example, if we look on the red graph below, we see that the probability of finding that electron decreases as the distance from the nucleus increases after a certain point.

#### NODES

A node is a surface on which the electron density is 0. They can be classified as either radial or angular. Where can you identify nodes on the diagram above?

Radial nodes occur at a fixed radius and are spherical in shape. The number of radial nodes is (nl-1). For example, the 4s atomic orbital contains 4-0-1=3 radial nodes.

Any node that isn’t spherical is angular. The number of angular nodes is l. Nodal planes and nodal cones are most common.

For your further information: The total number of nodes is n-1. The sign of the wavefunction switches when one crosses a node (the sign does NOT correspond to electrical charge).

#### GRAPHICAL REPRESENTATIONS OF ORBITALS

Pretty pictures! There are seven (!!!) methods for graphically representing the atomic orbitals of H. This is our last section, we’re almost done!

1. Radial functions (R(r)) and Radial functions squared (R^2(r))
2. Radial distribution function (RDF)
We ask, “What is the probability of finding the electron at a certain distance r from the nucleus, irrespective of angle?” So, we multiply the probability density by the volume of the associated spherical shell:
f(r) is the radial distribution function.
The maxima correspond to radii at which the electron is most likely to be found, while the minima correspond to radial nodes.
We can see that the most probable distance of the H atom electrons increases with increasing principal quantum number, which explains why an s electron has a great chance of being closer to the nucleus than a p electron, which is in turn more likely to be near the nucleus than a d electron.
3. Two Dimensional Polar Plots (Represents only the θ part)
The above representations don’t show how the probability depends on the angular coordinates, which specify the position of a point in space.
4. Three Dimensional Polar Plots (Represents both the θ part and the Φ part)
These polar plots will not show spherical nodes.
The 3-D polar plot for an s orbital is a sphere.
The three p orbitals (l=1) corresponding to the three ml values point in the x, y, and z directions.
There are five d orbitals (l=2) corresponding to the five ml values.
5. Probability Density Plots
We can represent the value of Ψ2 by the density of dots in a picture:
which provide radial and angular information. (Almost there! Hold on…)
6. Two-Dimensional Contour Maps
Similar to topographical maps of geographical regions, these maps show contours of constant electron density.
7. Three-Dimensional Contour Surfaces of Constant Probability
Typically, this is what you’re used to seeing in high school textbooks when looking at representations of atomic orbitals. It’s my personal favorite because it makes sense – we draw surfaces in space on which the value of Ψ2 is constant. These three-dimensional surfaces of constant probability are also known as isoelectron density surfaces. The 3d orbital The 2p orbital

Want to play around with these orbitals some more? Click here to find the program “Orbital Viewer”.

Congratulations for making it to the end of my post! You’re great (I know this was information at a more challenging level than casual, easy reading).

If I still leave any questions unanswered, please leave it in the comment section below and I will try my best to address them.

Keep checking back for more! (Or better yet, subscribe to my blog!)

Lots of love,

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This article has not been reviewed by Odyssey HQ and solely reflects the ideas and opinions of the creator.
Entertainment

## 25 Things Kids From the 2000s Will Be Nostalgic About

### The highlights of your childhood.

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The 2000s were a time that many young adults today can look back on, joyfully reminisce and somewhat cringe at the trends and the fads that we all used to love and adore. Here's a list of things from the golden 2000s that will have one feeling nostalgic about all of those times.

## 1. Wonderballs

One of the best candies that always seemed to catch your eyes at grocery store checkouts, leaving you begging your parents to get one.

## 2. iPod Nanos

The coolest and most colorful way to download your favorite boy bands and Hannah Montana jams.

## 3. Heelys

This magical shoe that made it fun to run errands with your parents.

## 4. Dance Dance Revolution.

The game that made the ultimate slumber party.

## 5. Silly Bandz

The more you had, the cooler you were.

## 6. "I love boobies" bracelets

The breast cancer bracelets that caused quite the controversy in middle schools.

## 7. Crimped hair

Because why wouldn't you want your hair to look as stylish as Lizzy McGuire's?

## 8. The "Muffins" or "Shoes" Youtube videos.

So stupid yet so funny.

## 9. Club penguin

You had the best pet puffles.

## 10. Skip Its.

Every garage had one.

## 11. Bratz Dolls and Polly Pockets.

What's better than oversized eyes and rubber clothing?

## 12. Baby Bottle Pops

Everyone's favorite cavity-causing candy.

## 13. Myspace

Where you lied about your age to get on and frequently rearranged your "top friends" lists accordingly.

## 14. Abercrombie models

Pictures like these were hanging in your room or your Razor phone background if you are a girl, and your inspiration if you were a boy.

## 15. Ferby

That creepy animal thing that everyone seemed to love.

## 17. Game Cube

Where you played Mario Kart, Super Smash Brothers, and more.

## 18. Slip 'N' Slides

The most fun you've ever had took place on one of these things.

## 19. Easy Bake Ovens

.

Where real baking did not take place.

## 20. Dunkaroos

The sugary snack that fit perfectly in your lunch bag.

## 21. Nintendo DS

The life changing device you probably used to play Nintendogs.

## 22. Drake & Josh

You strived to be as cool as them.

## 23. Play-Doh

A parent's worst clean-up nightmare.

## 24. The Sims 2

A legendary computer game.

### 25. Razor scooter

There was no cooler way to get around.

Student Life

## 7 Types Of Students You Will Meet In College

### You wish you could be #5, but you know you're probably a #6.

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StableDiffusion

There are thousands of universities around the world, and each school boasts its own traditions and slogans. Some schools pride themselves on sports, while others emphasize their research facilities. While there is a myriad of differences among each and every school, there will always these seven types of students in class.

## 1. The one who sits in the front row

StableDiffusion
There's at least one of these people in every single class, whether it's a required General Education class or an upper division major course. These students always sit in the front row and ask at least five questions every lecture. They attend all the discussions and office hours, and try to turn in homework at least a week in advance. These are also the people who remind professors about assigned homework and upcoming exams. Nothing bad about being studious, but are they even human?

## 2. The one who is always online shopping

Giphy
It doesn't matter whether it's fall, winter, spring or summer - these people are online shopping every single lecture. They usually sit a row or few in front of you, and while the professor is lecturing, instead of taking notes or even trying to act like they're listening, they just aimlessly scroll through Aritzia, Forever 21 and Zara. The only time their eyes ever leave their computer screen is when class ends, so they're basically just there for giggles.

## 3. The one who always falls asleep

Giphy
This person comes to class every day, but somehow never stays awake for more than 20 minutes. You can sometimes hear the occasional snore from a corner of a large lecture hall, or catch their heads nodding like a pendulum near the front of the class if they're the studious type. But let's be real here: we've all been one of those students at some point.

## 4. The one who never pays attention

Giphy
This category of students is probably the most common. Sure, they'll go to class, but all they do is surf through memes on Facebook or watch others play Fortnite. These people are in class for the attendance grade, not to learn. On occasion, they may raise their hand in class to ask a generic, vague question that has already been covered but hey, gotta get that participation grade. They're just doing everything they can to survive college, and honestly, it's a mood.

## 5. The one who never studies (but still aces the class)

Giphy
Standing as probably the most frustrating category of people in this list, these students won't know about a midterm until two days before. The day before the exam, they'll be chilling in Malibu and partying at night. They go to class every once in a while when the class time doesn't clash with one of their many elaborate social plans, but never pay attention. Somehow, they still ace all their exams and end up with the top grade in the class.

## 6. The one who is always stressed

Giphy
These people will start studying for a midterm at least two weeks before hand, and will be so stressed about homework and classes that they spend more time worrying about the workload than actually doing the work itself. They're in desperate need of a relaxing vacation that they're too stressed to plan, and they disappear from the outside world for weeks at a time. You can usually find them in a study room in a library, where they probably have been in for the past week.

## 7. The one you've never seen before

Giphy
You didn't even know that they were in your class to begin with because they never show up until it's exam week. Are they too smart for the class or struggling too hard to care? The world may never know. Maybe they're just straight chilling in their apartments being lazy, but most of time, they probably didn't even put this class on their schedules. Catch them going to Disneyland on a weekday at least once a month, which is more than the frequency that they attend class.
Lifestyle

## 8 Bible Verses To Uplift A Struggling Teenager

### God will never leave us nor forsake us

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Photo by Joel Muniz on Unsplash

Life is hard. There is no surprise there. It’s confusing and scary and hectic, but there are some amazing qualities, too. Sometimes you feel alone and don’t know what to do. School gets in the way of what you want to do or you’re dropping friends you thought you trusted. Everyone has their moments. Everyone has felt in the lowest place and couldn’t find the strength to get back up. But I want to help with that. Here are 10 Bible verses I hope will brighten your day, or at least make you feel stronger and happier.

Jeremiah 29:11

“‘For I know the plans I have for you,’ declares the Lord. ‘Plans to prosper you and not to harm you. Plans to give you a hope and a future.’”

It is hard to know what will happen in our life and sometimes it’s scary to think about how we lack that knowledge. But God has said He has great plans for us. He knows what will happen and it is our job to trust and obey Him.

red love free standing letter Photo by Carl Hunley Jr on Unsplash

Hebrews 6:19

“We have this anchor for the soul, firm and secure.”

Faith can be a tricky thing. “Do I really believe in this? I can’t see God. Is He really there?” These thoughts pass through everyone’s minds at least one point in time. Faith is a huge jump. But the outcome is amazing. Faith can move mountains. We just need to challenge it and figure out what we truly believe.

Joshua 1:9

“Have I not commanded you? Be strong and courageous. Do not be afraid; do not be discouraged, for the Lord your God will be with you wherever you go.”

I think it’s easier to say we all get a little fearful in life. Not everything goes as planned and it shakes us up. But it’s important to remember who we’re living for and why. If we’re too afraid to do what God has commanded us to do, we might not get to this place where He needs us to be. He won’t fail us. He won’t leave us. Instead of focusing on fear, try to focus on trusting Him. I know it’s hard, but trusting Him brings us one step closer to Him and where we need to be. And in the end, it will lead to a remarkable gift.

Exodus 14:14

“The Lord will fight for you; you need only to be still.”

God will never leave us nor forsake us. He is there for us in every little moment of every day. He cares for us and loves us and wants us. It’s always difficult to sit still and let God do His work, especially in a really tough time where we think we can handle things. But the truth is, we can’t. Not without Him.

woman meditating on wooden dock during daytime Photo by Le Minh Phuong on Unsplash

Luke 1:45

“Blessed is she who has believed that the Lord would fulfill his promises to her!”

This is an amazing reminder to be still and trust in God. He has blessed us and sometimes we take it for granted without realizing it. We need to trust that He will fulfill the promises He has given us. If we take a step back and look at the whole picture, we will realize He has been there for every little thing. He is there and wants us to hear Him. If we believe with all our heart that God will forever and always be there for us, then we will be able to trust Him. What is a better gift there than God? Let go and let God.

Psalm 61:2

“From the ends of the earth I call to you, I call as my heart grows faint; lead me to the rock that is higher than I.”

We all grow weak and weary. We need rest and faith that whatever we are going through, God will guide us. When we’re overwhelmed, it’s easy to shut our emotions off. But instead, we should give it to God. That doesn’t mean give it to Him and forget about it and think it is no longer our problem. Give it to Him and continually pray for it. Ask Him to guide us to that rock and help us defeat this trial.

Photo by Giulia Bertelli on Unsplash

Matthew 6:34

“Therefore do not worry about tomorrow, for tomorrow will worry about itself. Each day has enough trouble of its own.”

It is easy to worry and focus on the things going wrong rather than the things going right. When we worry, we are draining ourselves, leaving us tired and weary. And that is exactly what the devil wants. He whispers in our ears all the negative aspects of a day, which can easily lead to anxiety and worry. Be strong and try to focus on the positive things. It’s better to focus on at least one positive thought amongst a thousand negative ones instead of focusing wholly on the negative.

2 Corinthians 5:7

“For we walk by faith, not by sight.”

Faith is built on trust and love, even if we can’t see anything. In some cases, we might not think God is there simply because we can’t see Him. But He is there. We just need help looking at the bigger picture. Having faith isn’t something we say to try and convince ourselves that God is real and alive. It means we are taking a leap into this world, His world, even if we don’t know all the information. It’s okay to doubt sometimes, just as long as it doesn’t keep you from believing in our Savior. Faith is a heart thing. Why say we have a faith when deep down we know we don’t? We need to take that leap and remember that God will be there to catch us. He always has and always will.

person covering the eyes of woman on dark room Photo by Ryoji Iwata on Unsplash

Politics and Activism

## Buddy the Elf's Guide to Surviving Finals: 15 Tips for a Stress-Free Winter Break!

### "How'd You Sleep?" "Great, I got a full 40 minutes."

3159
jarviscity.com

Finals, the time we all dread. Amidst trying to juggle a social life, lack of sleep, exams, essays, and classes, it can be more than overwhelming to juggle this crazy season of life. Thankfully, Elf gets it. Here's 15 feels of finals week before winter break, as told by Buddy the Elf:

## When someone asks, "How'd you sleep?"

Anything greater than zero is a good night.

Honestly a lot like being hit by a taxi.

## Apologizing to your parents in advance for your GPA.

The perfect apology for any injustice, really.

## When your professor assigns another assignment on top of your finals schedule and suddenly you're trying to manage 100 responsibilities.

IT'S FINE I'M FINE EVERYTHING'S FINE.

## Stress Eating Everything In Sight.

PopTarts, Spaghetti, Marshmallows, Candy Corn….and Syrup.

## Kissing up to the professor for the sake of your grade.

Works like a charm.

LIAR.

## When your professor gets mad at your class for not turning something in on time

A very angry elf.

## Realizing you forgot to do an assignment.

Sheer, paralyzing panic.

## Having your sixth cup of coffee for the day.

*Pours in a bottle of syrup for the extra sugar boost.*

## Nearing the end and making plans with your friends for when you get home:

Only the essentials.

#NailedIt.

## Failing the final you thought you'd crush.

*Faceplant, broken limb, sadness.*

*Cries*

## Self-assuring yourself in the aftermath of finals, verbally and physically.

Now go take a nap and stress-eat some Christmas Cookies. You’ve earned it.

Featured

## 10 Pros And Cons Of Autumn

### Navigating the Season's Upsides and Downsides

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Personally, Autumn is one of my favorite seasons. The air is crisp but not too cold, there is so much to do, and you're not collapsing from the heat. I asked some friends and family what their favorite and least favorite parts of Fall. Below is the list I put together:

## 1. Pro: Leaves change color

The scenery changes from green leaves to orange, red, and yellow. The atmosphere brightens from the color change but dulls from the fog. It is a peaceful medium.

Photo by Aaron Burden on Unsplash

## 2. Pro: Clothes get cozier

Sweaters and long sleeves are starting to be worn without dying from the heat. However, shorts are still wearable without your legs freezing. Throw on shorts and a long sleeve shirt and you’ll feel comfortable in what you're wearing all day.

Photo by Heather Ford on Unsplash

## 3. Pro: Football!

Football is one of the best sports in the Fall. The tailgates create a closer community and the games bring students together while they cheer on their favorite teams. All in all, they create a lot of memories for everyone.

Photo by Riley McCullough on Unsplash

## 4. Pro: Peaceful walks

The air gets so cool, the wind is crisp all making long walks bearable. If you walk at night, you’ve probably seen a harvest moon - it is the best looking moon ever. The sky is clear and the moon is orange as if a pumpkin was sitting in the sky.

Photo by Ashleigh Robertson on Unsplash

## 5. Pro: Fun fall activities

Apple Picking is one of the most fun activities to do with a group of friends, your family, or even on a date. Another great fall activity is carving pumpkins. I remember when my brothers and I would sit at our kitchen table and carve pumpkins the day before Halloween. It was always so much fun.

Photo by Priscilla Du Preez 🇨🇦 on Unsplash

## 6. Pro: Start of holidays

When fall rolls around so do the holidays that follow: Halloween is right around the corner and then Thanksgiving is next, the day where you can eat as much as you want without being judged. However, always remember the meaning behind this holiday. While you shove food in your face, remember to be thankful.

Photo by Sebastian Coman Photography on Unsplash

## 7. Con: Allergies and colds

As the cool weather begins, the colds and allergies follow in its track. No one likes being sick especially in such a great season. Allergies are definitely a con.

Photo by Diana Polekhina on Unsplash

## 8. Con: Inconsistent weather

During Fall, there is nice crisp weather in the morning then as the day goes on it gets hotter and hotter. At night, it is very cold compared to earlier that day. The weather fluctuates too much which makes choosing an outfit pretty difficult.

Photo by Craig Whitehead on Unsplash

## 9. Con: Raking leaves

This is a chore that is not fun for anyone. Once you have all of the leaves picked up, you want to jump in the pile, spreading out the leaves again just so you can jump back in. It is torturous cycle.

Photo by michael podger on Unsplash

## 10. Con: Summer is over and winter is coming

Winter is without a doubt my least favorite season. I get cold very fast and I don’t like it. During fall I can bear the cold weather because it is not completely freezing, it’s cool– there’s a difference.

Photo by Aaron Burden on Unsplash