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Chemistry
Fizban140
Registered User, __BANNED USERS regular
Registered User, __BANNED USERS regular
Just took a chemistry quiz online, got 3/10 the first time and then 7/10 the second and final time.
1. Which of these elements has two s and six p electrons in its outer energy level?
a. He
b. O (my answer, it should be argon now that I read it I think)
c. Ar
2. As the wavelength of a light wave increases, its frequency and energy both decrease.
True
False (mine, book states this exactly, not sure why it is wrong)
3. An atom of nitrogen has two elections in a 1s orbital, two electrons in a 2s orbital, and one electron in each of three different 2p orbitals.
True
False (mine, I did the math and everything, not sure why this is wrong. Shit just looked, I meant to put true and I put false I guess....whatever)
Those are the ones I got wrong. No idea why, it was open book and I know the material. I got 10/10 on the previous two quizzes but this just doesn't make sense to me, I used the interet and the book for each answer and still got 3 wrong.
Anyways I am really not understand chemistry at all, there is just so much random stuff and it doesn't even feel remotely related to science. All we do is memorize things and there is rarely an explanation because we wouldn't be able to understand or we go into it later. I can't learn like that, I have to know why or it won't make sense to me, if there isn't a reason something works than it isn't worth remembering for me.
Does chemistry get better? If not I am changing my major.
1. Which of these elements has two s and six p electrons in its outer energy level?
a. He
b. O (my answer, it should be argon now that I read it I think)
c. Ar
2. As the wavelength of a light wave increases, its frequency and energy both decrease.
True
False (mine, book states this exactly, not sure why it is wrong)
3. An atom of nitrogen has two elections in a 1s orbital, two electrons in a 2s orbital, and one electron in each of three different 2p orbitals.
True
False (mine, I did the math and everything, not sure why this is wrong. Shit just looked, I meant to put true and I put false I guess....whatever)
Those are the ones I got wrong. No idea why, it was open book and I know the material. I got 10/10 on the previous two quizzes but this just doesn't make sense to me, I used the interet and the book for each answer and still got 3 wrong.
Anyways I am really not understand chemistry at all, there is just so much random stuff and it doesn't even feel remotely related to science. All we do is memorize things and there is rarely an explanation because we wouldn't be able to understand or we go into it later. I can't learn like that, I have to know why or it won't make sense to me, if there isn't a reason something works than it isn't worth remembering for me.
Does chemistry get better? If not I am changing my major.
Fizban140 on
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Have you tried talking to them during office hours?
And it's why I changed my major, too.
Secondly, you need more instruction in understanding the periodic table if you don't yet understand the numbering and the jumps between S, P, and D orbitals.
What made you become a chemistry major in the first place?
E = hf
v = c = f*(lambda) (this is a basic wave velocity, frequency, wavelength relationship. c is the speed of light)
Do some algebra and convince yourself that as wavelength (lambda) increases, its frequency decreases. Thus its energy also decreases. You must be misinterpreting the textbook somehow, because the answer IS supposed to be true.
I switched out of physics into math this semester (second year). All sciences are full of having to memorize key things. If you don't "speak" math well (I'm talking large PDEs, Schrodinger's equation is just the tip of the iceberg) then physics won't be your bag. I made it through first year chemistry with the aid of memorization.
Not much of the material I learnt in first year second semester chemistry was explained in terms of first principles. I think you're experiencing something most chemistry students do in first year.
I'll also echo Tofu's sentiments by saying that any science field has a lot of facts that you'll need to initially just accept as truths without knowing why, because explaining why they are true would require a much higher understanding of the topic than someone starting out could ever have. Also, definitely do not go into bio if memorization of facts is not something that you enjoy doing.
Edit: Your opinion also may differ based on how the course is taught. Starting with our organic chemistry sequence all the reactions are broken down into first principles so you should know why something like a wittig reaction goes and not just memorize what happens.
(I am not a university advisor! I am still registered as a Physics Major, for example, until I decide if I want to do Math Honours or Major at the end of this semester. Nobody cares at Dalhousie)
Ok, I reread the original post and the thread and you are still not getting much love from the third question.
Orbitals are annoying, but the way they behave give some interesting properties of metals. For example, Nitrogen is not quite as reactive as its place in the periodic table would suggest. This is because the 2p orbitals fill up with the electron spins matching. That is, rather than having one full orbital and one half full one, you have three half-full orbitals that have the spin of their electrons going the same way.
The same thing happens for Mn. (move down the column for similar properties)
Part of why Cu, Ag, and Au are such good conductors are another example of why orbitals are worth knowing a bit about. Rather than filling the s and almost filling the d orbital, for these elements the d orbital fills completely and leaves one valence electron in the s orbital (a weakly held electron).
And then there's anti-bonding and bonding orbitals when considering molecules, which will be a real headache. But the main thing is to get comfortable with what orbitals represent, and how they behave.
Chemistry is all about stability. Systems tend to their most stable states.
Chemistry is math and memorization heavy. Organic chemistry was my personal hell and that's as far as I had to go for my Bio degree.
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You have to remember that as the frequency of a wave increases, it will carry more energy. Just accept it.
Now, if your frequency is increasing then your wavelength (or period) is actually decreasing (that is, the peaks of the waves are getting closer together). If your frequency is decreasing then your wavelength is increasing (the peaks of the waves are becoming further apart).
My freshman year I rushed into a 4 year university in a computer science and engineering program and hated it, but I couldn't take any other classes outside of the program since they railroad kids through to get them out in 4 years. The best choice I ever made was withdrawing (in good standing) and attending a community college for 2 years while I decided what degree I wanted and then transferring to a 4 year school for another 2 years to complete my degree.
For 2, as others have said the energy of a wave is related to its frequency. Maybe you're thinking of the speed of the wave, which would stay the same for every electromagnetic wave.
For 3, you spread electrons across orbitals of equal energy first, then start to double up the electrons. Electrons like space like that, but less so than they like being in a lower-energy orbital.
I was actually in a similar position as you, just sort of picked chemistry as a major and went with it. Gen chem was kind of interesting to me, but mostly for the labs, then organic chemistry was a bitch and a half. I really, really enjoyed learning about the transition metals though. Now I've graduated and actually work as a chemist, and although I could have easily picked something else and maybe even would have enjoyed it more, now I feel like I *am* a chemist and don't want to leave the field. The good thing about college, though, is that you can take all sorts of different classes and see what appeals to you.
I remember you've had some issues with math on here in the past. I would rethink the sciences. In all honest, biology might be better suited for you. Chemistry is pretty math heavy (as is most majors in the sciences). I think you need to take a few more classes in a different focus, see what you're good at (and if you enjoy it).
There can only be one of each type of subshell (s,p,d, etc.) in any given energy level, or electron shell. Level 1 (the innermost shell) contains 1 subshell. The next one contains two of them. All you need to memorize is the non-alphabetical nomenclature (s,p,d,f,g): shell (or energy level) 1 contains only an s subshell; shell 2 contains an s and a p; shell 3 contains s, p and d; shell 4 contains s, p, d and f; etc. These are often named 1s, 2s, 2p, 3s, 3p, 3d, etc.
The maximum number of electrons allowed at each subshell starts with 2 (in the s subshell) and increases by 4 for each of the further subshells. In other words, 2, 6, 10, 14, etc. As far as I know, subshells up to 3p are always filled to the maximum allowed number; beyond that, it gets tricky. In other words, for any element up to atomic number 18 (Argon), this problem can be solved just by looking up the total number of electrons in the Periodic Table, then filling each energy level in order.
But there's a simpler way. Based on the above, your problem can be read as: "Which of these elements has at least 8 electrons (2 s + 6 p) in its outer energy level?" This in turn means that your element must have at least 10 electrons in total, because there must also be an innermost energy level with exactly 2 s electrons. Check out the Periodic Table; of your three elements, the only one with an atomic number of 10 or more is Argon (18).
You don't have to memorize a lot of stuff, but you do need to accept the fact that you need to consult resources like the Periodic Table a lot.
Either your book is wrong or you're misreading it. Note that the speed of light is constant, so you can't treat this as a mechanical wave. The wavelength of light is inversely proportional to its frequency and energy (higher frequency = higher energy). Frequency f = c/l, where c is the speed of light (constant) and l is the wavelength. So the statement in the problem is True.
See my comment on problem #1. Nitrogen's atomic number is 7, so it has 2 * 1s electrons, 2 * 2s electrons, and 3 * 2p electrons (or you can use this super handy table derived from the periodic table). The subshells are composed of atomic orbitals, each of which can hold 2 electrons (thus s subshells have one orbital, p subshells have 3, d have 5, etc.); whenever possible, each electron likes to occupy its own private orbital. So yeah, there are three 2p orbitals, and three 2p electrons, so you do have one electron in each of three different 2p orbitals.
Sounds more like poor teaching than a problem with the subject. But in every applied field, like chemistry or biology, there's a certain set of basics that you just have to accept at face value, or else you'll go insane trying to understand the root cause for everything. Because ultimately the atomic orbitals are about quantum physics. You just need to have a working knowledge of atomic electron configuration in order to make any sense of how atoms interact with each other and with photons. Everything else follows logically from that. So to answer your question, yeah it probably does get better.
Yes, if you specialize in something with medical or industrial applications. Or if you're motivated and good at what you do. That's how I see the European job market anyway; no idea about the U.S.
This is true of pretty much every major and profession at this point.
Secret Satan
K 4s1 Ca 4s2 that makes sense to me since I guess they act like elements above it so they have to have similar valence shells...now why does it go V 3d3 Cr 4s1 3d3 then back to Mn 3d3 I don't get it.
Two images on there to pay attention to are:
and
This fill order is because energy levels are actually split.:
So I am just suppose to suck at math and never get better? I haven't done math in like 6 years, and when I took math classes in school I didn't even really do it, there was never a need. I just cheated and on the homework and bullshitted the tests and passed every class.
Going into a career without job potential is for idiots, it is a huge life and financial decision. Spending $40,000 and four years of your life on college better have a nice pay off, if not you are sort of fucked in life.
I didn't just pick a major, I enjoyed biology and the chemistry parts of it so I am trying to narrow down a science.
FWIW: Quantum and orbital structures will not make solid sense to you without multiple years of chemistry and mathematics behind your belt, as well as basic physics. You aren't asked to know these things in detail at your level, mainly because it would both drive you insane and be way above your head. The best part about a chemistry major is that EVERYTHING and I mean EVERYTHING you learn will come back in another class in greater and more glorious detail. Trying to pretend you don't need to know it because it doesn't have a point right now is futile if you want to stick with chemistry.
That being said, follow aufbaus rule, be able to draw the thing on your test and then profit! If you know how electron orbitals fill, which you do from aufbaus filling rule, you can figure out orbital diagrams. It can be daunting, based on the amount of letters you end up with, but just remember that those are shorthand for stuff you would never want to write out all the way.
ALSO HERE IS THE MOST FANTASTIC HINT EVER:
The period table already holds all the info you need, you just have to know how to extract it!!!!
Man I am probably not smart enough for physics either, mind as well not even try that. I should just become an english major and work at starbucks.
That is the joke right?
Most biology and science jobs that pay well require at least a masters. If you don't like something, don't make it your major. If you enjoy politics and composition, do political science. People may say "useless degree", but you can still get a corporate job with any major, really.
P-Chem and P-Chem lab were the most difficult classes I've ever taken and I don't envy you. I sometimes wake up at night in terror thinking I've forgotten about a lab report.
I didn't really do that great in general chem and I actually found organic chem to be much easier for me to wrap my head around. Don't be upset if you don't understand all there is to know about chemistry in two semesters. As someone mentioned previously, it is a new language and it takes a while to understand what the hell it means.
I ended up getting a degree in biochemistry and really enjoyed the biology aspect more than the chemistry but was too close to finishing my chem degree and I wanted to get the hell out of undergrad. When I started looking for jobs about 2-3 years ago I had an extremely difficult time (read: impossible) finding anything. Now I'm back in school. Yay.
Also, I wouldn't be too discouraged yet about Chemistry. I was great at it in high school, and then got to college and struggled with the pace of gen chem my first semester. I eventually realized that I was studying like I was in high school (hardly at all) and that I just needed to put a little more effort in.
About your complaint about "random stuff" I think you'll run into that with any freshman-level science class. You just don't have enough of a background in the subject yet to understand the real physical/chemical reasons for many of the things you learn. A lot of it you just have to accept for now and memorize. That said, some professors are better than others, a good professor will probably provide a context for what you are learning. That is where a tutor could really help you, by giving you a different perspective on the material.
My advice would be to go with that and look at your endgame. What do you want to be doing? If you're down with chemistry, start thinking about being a chemical engineer. Talk to your chem professors and get some contacts and talk to them. See if you can set up a shadowing at their work.
I say this because it doesn't seem like you love the science, so you better make damn sure you love the job. I have friends that are chemical engineers, and it's not an easy job (though they do make bank pretty much right out of college- caveat- they had to move cross country to advance their careers).
If you don't have a particular passion, it's much more helpful to think about the actual careers and lifestyles that go along with a given field.
I don't know what my passions are, I like games? That doesn't help me, I mean I never thought of rigging up a hot air balloon outside my 3rd story window, or starting to grow bacteria in dishes for fun, but I don't think that means I hate science.
I have no fucking clue about where I want to work, like I have said before I just know it isn't in the military. I don't want to work on aircraft and I don't want to work outside all the time. I hate jobs that don't keep you mentally engaged, things that keep you busy make time go by faster.