Physics and Chemistry?

TehFionnster

Hey LC Forum'ers


Just wondering about picking my subjects for LC
We have to pick them in like 3 weeks?
But Are physics and chemistry difficult but interesting? (Two seperate subjects)
I think biology is out of the question because the teacher is rediculously stupid and doesn't know the course.
But Just some general info on Physics and Chem would be appreciated

Chuchoter

Doing all three, they're all brilliant if you like science. Physics is a lot easier than people say and since you see it in everyday life its a lot easier to understand. However I don't think it will work if you are a learn by heart no thinking kind of person. There is a hell of a lot in Chemistry and its the hardest but I have a **** teacher, its interesting though and is a great basis for a lot of science-y courses.

partyatmygaff

Biology is probably the easiest out of all of them (Almost all of it is rote learning, very little that you need to "understand" as such).

Physics is the in between in terms of difficulty and course length.

Chemistry is the shortest but also the most challenging in terms of what you need to understand. (It's also the most interesting and has the best experiments but i'm a bit biased :pac: )

As a general rule you do either Physics/Chemistry or Chemistry/Biology. Both pairs complement each other in some way or form i.e.
Enzymes -> Rate of Reaction (Biology/Chemistry)
General Atomic theory (Physics/Chemistry)

Nothing really links physics and biology though but it's still a fine combination.

TehFionnster

Thanks for the great replies

But I'm definatley not into rote learning, I'd much prefer to learn 3 hours Irish grammar than learning off an essay(just using Irish as an example), I much prefer to understand

partyatmygaff

TehFionnster wrote: »

Thanks for the great replies

But I'm definatley not into rote learning, I'd much prefer to learn 3 hours Irish grammar than learning off an essay(just using Irish as an example), I much prefer to understand

Actually it's better to show you a few examples of the hardest you can be asked in all three exams just to give you an idea of what each one is like

Chemistry

Phosphorus(V) chloride decomposes into phosphorus(III) chloride and chlorine at a temperature of
500 K according to the following balanced equation.
PCl5 (g)
PCl3 (g)
+ Cl2 (g)
(a) This is a reversible reaction and a dynamic equilibrium is reached.
Explain the underlined terms. Why is the equilibrium described as dynamic? (11)
(b) State Le Châtelier’s principle.
Write the equilibrium constant (Kc) expression for the above reaction. (12)
(c) When 208.50 g of phosphorus(V) chloride is heated in a 100 litre container at a temperature of
500 K equilibrium is established with 53.25 g of chlorine gas present in the container.
Calculate the value of the equilibrium constant (Kc) for the reaction at 500 K. (12)
(d) When the temperature of the equilibrium mixture is increased, the phosphorus(V) chloride
decomposes further. Is the reaction endothermic or exothermic? Justify your answer. (6)
(e) What change, if any, would an increase in pressure have on the value of Kc? Explain. (9)


Write the electron configuration (s, p, etc.) of the oxygen (oxide) ion (O2–).
(b) State two differences between Mendeleev’s periodic table and the modern periodic table of the
elements.
(c) What are the two possible shapes of molecules of general formula QX2?
(d) How many atoms of iron are there in a 30 g bowl of cornflakes that contains 0.0024 g iron
per 30 g serving?
(e) State Gay-Lussac’s law of combining volumes.
(f) Define activation energy.
(g) Distinguish between sigma (σ) and pi (π) covalent bonding.
(h) What is an ideal gas?
(i) What happens during the secondary stage of sewage treatment?
(j) Draw the structural formulae of any two molecules with the molecular formula C3H6O2.
(k) Answer part A or part B.
A Write a balanced equation for the reduction of iron(III) oxide by carbon monoxide in a blast
furnace.
or
B Write a balanced equation for the reaction that occurs when sulfur dioxide from industrial
gaseous emissions dissolves in water.
____________________________

Biology

Part (a) deals with DNA structure and replication.
(a) (i) Name the base in DNA that pairs with cytosine.
(ii) What are the two main events in the replication of DNA? (9)
Part (b) deals with protein synthesis.
(b) (i) Explain the terms transcription and translation.
(ii) In which structures in the cell does translation occur?
(iii) How many bases in sequence make up a codon in mRNA?
(iv) Each mRNA codon specifies one of three possible outcomes during protein synthesis.
Name these three possible outcomes.
(v) What does the letter ‘t’ stand for in tRNA?
(vi) During translation one end of a tRNA molecule attaches to an mRNA codon.
What is usually attached to the other end of the tRNA molecule? (27)
(c) Distinguish between the terms in the following pairs by writing one sentence about each
member of each pair.
(i) Haploid and diploid
(ii) Homozygous and heterozygous
(iii) Genotype and phenotype
(iv) Segregation and independent assortment.


Answer five of the following by filling in the blank spaces.
(a) In relation to the human diet, what is meant by a trace element? ……………………………………
………………………………………………………………………………………………………….
(b) Give an example of a trace element .…………………………………………………………………..
(c) State one way in which an oil differs from a fat ………………………………………………………
(d) Vitamins may be divided into two groups depending upon their solubility.
Name these two groups.
(i) ……………………………………………………………………………………………………....
(ii) ……………………………………………………………………………………………………..
(e) What is a triglyceride? ………………………………………………………………………………..
(f) Give an example of a catabolic reaction in a cell …………………………………………..................

Physics

What is thermionic emission? (6)
X-rays are produced when high-energy electrons collide with a target.
Draw a labelled diagram of an X-ray tube. (12)
What are X-rays and how do they differ from light rays?
Give two uses of X-rays. (18)
When electrons hit the target in an X-ray tube, only a small percentage of their
energy is converted into X-rays. What happens to the rest of their energy and how
does this influence the type of target used? (9)
A potential difference (voltage) of 40 kV is applied across an X-ray tube.
Calculate:
(i) the maximum energy of an electron as it hits the target
(ii) the frequency of the most energetic X-ray produced. (11)
(Plank constant = 6.6 × 10–34 J s ; charge on electron = 1.6 × 10–19 C)
fan
A
B
230 V M
fuse
coil




The history of anti-matter begins in 1928 when a
young English physicist named Paul Dirac
predicted an anti-particle for the electron.
(i) What is anti-matter?
An anti-matter particle was first discovered during the study of cosmic rays in 1932.
Name the anti-particle and give its symbol.
What happens when a particle meets its anti-particle? (18)
(ii) What is meant by pair production?
A photon of frequency 3.6 × 1020 Hz causes pair production.
Calculate the kinetic energy of one of the particles produced, each of which
has a rest mass of 9.1 × 10–31 kg. (21)
(iii) A member of a meson family consists of two particles.
Each particle is composed of up and down quarks and their anti-particles.
Construct the possible combinations.
Deduce the charge of each combination and identify each combination.
What famous Irish writer first thought up the name ‘quark’? (17)
(speed of light = 3.0 × 108 m s–1; Planck constant = 6.6 × 10–34 J s)

Now I know you're just looking at going :eek: but there's a big difference between JC Science and LC Science subjects. Don't let any of the above put you off either, I chose the most challenging of questions to show you the peak of what's expected from each subject.

TehFionnster

partyatmygaff wrote: »

Now I know you're just looking at going :eek: but there's a big difference between JC Science and LC Science subjects. Don't let any of the above put you off either, I chose the most challenging of questions to show you the peak of what's expected from each subject.

Yeah,That was my face exactly, Chemistry looks unbelievably difficult, biology, I don't know not doing it :P, Physics Looks OK but still pretty difficult

partyatmygaff

TehFionnster wrote: »

Yeah,That was my face exactly, Chemistry looks unbelievably difficult, biology, I don't know not doing it :P, Physics Looks OK but still pretty difficult

They all look exceptionally difficult now and believe me I was kicking myself back in third year after I took a look at the exam papers. Actually doing the course though made me see that it's really not too bad at all. Chemistry looks difficult but if you love it (As I do) and have a great teacher than you'll find it very doable. Physics and Biology the same.

Just Like Heaven

I do all three.

Biology is cool, but i have an excellent teacher.

Physics is way easier now because of the fantastic new log tables.

Chemistry (even moreso than physics) requires revising notes from day one. BUT in my opinion it is the most rewarding and interesting subject, it's great.

Chuchoter

Fewtinsofroth: We both do all three!

I think so far biology is the most boring (we move so slowly in class). Chemistry has the best experiments. I think the main thing to keep in mind is to stay on the ball from day one. Study/write notes from the beginning, it builds up incredibly quickly (3 days and you're looking at pages of notes to write). I think the best part about the sciences is that they are interesting. I like being in class and I'm like ooh thats interesting or I'll be in class and there will be a projector in front of the board and you move your head to see the board and its like theres an example of parallax (god I'm a nerd). These kinds of things don't happens so much in accounting :P

Just Like Heaven

crayolastereo wrote: »

Fewtinsofroth: We both do all three!

I think so far biology is the most boring (we move so slowly in class). Chemistry has the best experiments. I think the main thing to keep in mind is to stay on the ball from day one. Study/write notes from the beginning, it builds up incredibly quickly (3 days and you're looking at pages of notes to write). I think the best part about the sciences is that they are interesting. I like being in class and I'm like ooh thats interesting or I'll be in class and there will be a projector in front of the board and you move your head to see the board and its like theres an example of parallax (god I'm a nerd). These kinds of things don't happens so much in accounting :P

I do agree. Overall i would recommend both physics and chemistry (probably chemistry a bit more cause it's the most interesting) but if your quick at maths then physics. But you do very much have to be on top of them from day one. :rolleyes:

jumpguy

I do all three, and tbh, looking at questions of biology, chemistry or physics make it look much harder when you've no idea what anything means, so it's a pointless exercise imo...

Biology - Lovely subject. Rote learning implies just learning without understanding, however, if you understand and like biology, the learning is quite easy. It's the longest of the three, and probably my favourite. If you've an interest in biology any bit (like human systems, DNA) then I'd recommend it. Good bit of practicality in it too, with lots of interesting experiments. However, I do have a very good biology teacher. I think it's such a great pity that students' choices are limited by poor quality teachers...

Chemistry - Definitely competing with biology for my favourite subject. Nice enough exam papers in it, quite predictable, subject is great if you, once again, have an interest in it. Paying attention in class is quite important and I would argue that having a good teacher is quite important too. The course is short enough and there's a good bit of interesting experiments. That said, there is learning in it too, but it's all easier if you understand it.

Physics - My least favourite science - but not by much. Mainly because the experiments aren't as exciting and the first part of the course (about light and mechanics) is fairly dull imo. If you're good at maths though, then that element should be no problem, especially with the new log tables. Once you've the maths down, it's just learning of the many definitions of the course. There is an understanding required for physics too though, especially later in the course! In fact, I'd say understand is just as important as it is for chemistry. Very difficult to rote learn some stuff in it without understanding (for example, how diffraction grating works).


It's hard to give you an accurate picture, choosing science you have to go with what you're interested in, NOT what people say is easier. That opinion differs for everyone.

Best of luck!

nommm

I don't do Physics but I do Chemistry and Biology. Biology is ridiculously easy if you are willing to study it. Chemistry is quite difficult and the marking schemes in the exam are a bitch. You have to be very specific. It's a very interesting subject though and I always have fun doing the experiments. That might be because I'm a bit of a nerd when it comes to Science though. I decided not to do Physics because hated it with a passion for the JC but friends I have that do it say it's interesting.

Fad

Physics is fairly straight forward, once you understand mechanics and whatnot you're set. You dont even need to learn off all the equations now!

Chemistry can be tough in parts, some of it is so simplified that it actually becomes hard to understand in the grand scheme of things. Iunno, I LOVED it, but it wasn't an easy subject. (Doing it in college now!)

HyperSkypeWiper

TehFionnster wrote: »

Hey LC Forum'ers


Just wondering about picking my subjects for LC
We have to pick them in like 3 weeks?
But Are physics and chemistry difficult but interesting? (Two seperate subjects)
I think biology is out of the question because the teacher is rediculously stupid and doesn't know the course.
But Just some general info on Physics and Chem would be appreciated

imo, physics is interesting and not too hard if you're good at maths. chem is not at all interesting and hard.
I would just do physics if i didn't need chem.:)