CHEMISTRY COMMUNITY

nelquosey

You need to consider that a T shape has different bond angles within it, they are not all identical.

nelquosey

given the mass and the velocity you can use the DeBroglie equation to figure out the object in motion's wavelength. This is useful when you are attempting to figure out the wavelength of a particle or a body of mass.

nelquosey

I think that we should know how to do all the VSEPR shapes that were showcased and worked through in class, and in the homework problems. Good luck (:

nelquosey

lone pairs each have a negative charge, and they also have to respond to the charges of the atoms, making them push in the directions that they do push in. Think of it as a bunch of magnets of identical charges.

nelquosey

All atoms have the capacity but it depends on the whole molecule. You want to make it as stable as possible.

nelquosey

Think of the electron charge, because electron pairs are negatively charged they repel other negatively charged particles, like other electron pairs. They also repel molecules but not with the same force that they do lone pairs.

nelquosey

I would draw the direction of the arrows, if you look like they are positioned in obvious opposite directions, they cancel out. If it is not obvious I would draw vector diagrams like in high school physics, determine the x and y components and figure out whether or not the directions cancel the magn...

nelquosey

How do you know when atoms can break the octet rule? or which atoms can break the octet rule? These are just exceptions that need to be memorized, but I don't think we need to worry too much about them. just be familiar in general with the idea that there are atoms that do not agree with the octet ...

nelquosey

I googled your question and came across someone who had the same question as you back in 2011:
viewtopic.php?t=4306
I hope the replies help :)

nelquosey

Hydrogen can either have a charge of positive or negative 1 but since Aluminum already assumes the positive charge, you use the Hydrogen charge of 1- to construct your formula :)

nelquosey

It is definitely UV light as proven by the Ultraviolet catastrophe.

nelquosey

I like to use the group numbers and subtract 10 as we approach the non-metals.

nelquosey

I believe that it's fine to use lines since Dr. Lavelle uses dots simply to erase confusion before delving into the concept. I think moving forward we will be using the system of lines in class.

nelquosey

We went over atomic radius, ionic radius, ionic energy and electron affinity in class.

nelquosey

I find it really helpful to watch videos on the concept, I like Crash Course Chemistry. I watch the video and take notes on it. It's also helpful to explain the concept to other people. If you can explain the concept without using notes you have a full understanding of the concept.

nelquosey

No, Noble gasses have a full valence shell and do not need any electrons to become stable.

nelquosey

An ionic bond is the transfer of electrons from an non-metal to a metal, a covalent bond is when two non-metals share electrons and metallic bond is when a metal exists within a mass of electrons.

nelquosey

I would use the one we learnt in class to get my answer and use the high school one to check my answer.

nelquosey

I believe they will be handed back in discussions either way but if you can't make it, go to either your TA's office hours or Dr. Lavelle's :)

nelquosey

I would put extra effort into having a full understanding of the concepts. Once you've got calculations down and have done the practice, focus more on the concept behind that calculation. There is no point in practicing redundantly if you don't understand what your calculations mean or what the foun...

nelquosey

A photon is a packet of energy or light whereas a particle is a subatomic unit such as electron, neutrons and protons. Also, traditionally photons do not have masses whereas particles do.

nelquosey

Since it's a one photon to one atom to one electron interaction increasing the number of photons (increasing the intensity) should increase the number of electrons ejected, this answers your second question. However, you need to keep in mind that different metals have different work functions and th...

nelquosey

I like to think of a photon as a packet of light/energy.

nelquosey

If you think about the equation for kinetic energy you see that Ek=(1/2)mv^2. (1/2) is a constant and has no units. Mass has units in Kg and velocity is measured in m/s. The equation asks you to square velocity and if you think about your exponent laws (m/s)^2 comes out to be m^2/s^2. This equation ...

nelquosey

I suggest using unit cancellation or dimensional analysis to solve questions like these. You have all the equations you need and the givens required to use simple cancellation and number crunching :)

nelquosey

I would just be prepared in general with a founded understanding. Also I suggest that you do all the limiting reactant questions that were "assigned" for homework :)

nelquosey

I believe that the speed of light with the exact number of sig-digs preferred by Dr Lavelle is on the formula sheet given to us in tests :)

nelquosey

To calculate anything about frequency or energy you would need to be given wavelength. This question is testing general knowledge of electromagnetic radiation. The question assumes that you know the order.

nelquosey

I am sure that Dr. Lavelle will make it clear when he switched from one to the other :)

nelquosey

Because actual yield depends on side reactions, human error, and other experimental mishaps, it is hard with our level of understanding of chemistry to measure actual yield. As of now we have been calculating chemical problems within a very theoretical and almost perfect sphere, where reactions are ...

nelquosey

In the test we will be given a periodic table and I would assume that we are meant to use whatever version of the atomic mass that the table specifies :)

CHEMISTRY COMMUNITY

Search found 31 matches

Re: T-Shape

Re: DeBroglie

Re: Trigonal bipyramidal and octahedral family [ENDORSED]

Re: Atom vs lone pair

Re: Double/Triple Bonds

Re: Bond angle

Re: Cancelling out dipole moments

Re: Octet rule

Re: Which is more Ionic

Re: 3.25 c)

Re: Incoming Light [ENDORSED]

Re: VALENCE ELECTRONS [ENDORSED]

Re: Dots or lines [ENDORSED]

Re: Trends? [ENDORSED]

Re: Conceptual Questions

Re: Valence shell on Noble gases

Re: Ionic vs Covalent vs Metallic Bonds

Re: Equation

Re: Returned midterms

Re: test 2

Re: Difference between photon and particle?

Re: Frequency on Photoelectric Effect

Re: still don't uderrsatnd what a photon is [ENDORSED]

Re: 1J=1kg.m^2.s^-2

Re: Calculating energy [ENDORSED]

Re: Knowing if it's Limiting Reactions

Re: HW 1.7 (speed of light) clarification

Re: HW 1.5 [ENDORSED]

Re: Lecture Outlines [ENDORSED]

Re: Actual Yield [ENDORSED]

Re: Rounding atomic weight (general question) [ENDORSED]