CHEMISTRY COMMUNITY

Catherine Kim 3K

Br is below F on the periodic table, so it is bigger.

Catherine Kim 3K

The formula [symbols] should be alphabetical and you put metal at the beginning. The neutral molecule should be at the end. You need the brackets to show the charge.

Catherine Kim 3K

Amphoteric substance is a molecule/ion that can act either as an acid or base. They should have transferable H and atom with lone pair electrons.

Catherine Kim 3K

Generally the atom with the lowest ionization energy is the central atom.

Catherine Kim 3K

You should first draw a Lewis structure. Then, there are multiple methods to see if the structure is polar or nonpolar. You should check the polarity of bonds, the electron groups around the central atom, and symmetry of the molecule.

Catherine Kim 3K

The arrow should point towards the negative charge.

Catherine Kim 3K

Sigma bond is formed by end-to-end overlap of atomic orbitals while pi bond is formed by side to side overlap of atomic orbitals. Also sigma bonds tend to be stronger than pi bonds.

Catherine Kim 3K

Double bonds are stronger than single bonds because double bonds add stability to compounds and restrict rotation around the bond axis. Double bonds have sigma bonds and pi bonds; double bonds are also shorter than single bonds because the extra bonding electrons pull atoms closer together.

Catherine Kim 3K

The element with the smallest electronegativity is the central atom.

Catherine Kim 3K

Yes. Van der Waals forces is a general term used to describe the intermolecular forces between molecules. There are two types of Van der Waals forces - London dispersion forces and dipole-dipole forces.

Catherine Kim 3K

Polarizing power does not only apply to cations. Anions also have polarizing power; larger anions will have greater polarizing power.

Catherine Kim 3K

The electronegativity of the atoms will be different in a polar bond. Yet, the electronegativity of the atoms will be equal in a nonpolar bond.

Catherine Kim 3K

To see if your Lewis Diagram is the most likely arrangement is to first make sure you follow all the steps. 1. Count total number of valence electrons on molecule. 2. Draw single bonds between atoms. 3. Count how many electrons remain and assign them as lone pairs to fill valence shell. 4. If there ...

Catherine Kim 3K

I use the least ionization energy to determine the central atom. Also, you could also look look for other clues to determine central atom: H is always at the ends, O is usually the one that has double bonds with another element, etc.

Catherine Kim 3K

You calculate bond lengths by finding the mean/average of the given lengths. You also need to check if it is a resonance structure or not.

Catherine Kim 3K

The electron configuration of Mn is [Ar]4s2 3d5. Therefore, it has 7 valence electrons. Also Mn is a transition metal so it would have incomplete d subshells.

Catherine Kim 3K

Atomic radius of atoms decreases from left to right (exception is the oxygen radius being slightly greater than nitrogen radius) because protons are being added to the nucleus and so electrons are being added too. Since electrons are being pulled closer to nucleus, the size of atoms decreases.

Catherine Kim 3K

First ionization energies increase from left to right on the period table. Electron shielding affects ionization energy.

Catherine Kim 3K

Why is the electron configuration for Ytterbium [Xe]4f14 6s2 and not [Xe]4f13 5d1 6s2?

Catherine Kim 3K

The rule is to write 5s e- after 4d e-. As for silver, d^10 has lower energy. A lower total energy may be achieved if an electron enters a 4d orbital instead of expected 5s orbital, if that arrangement completes a full subshell. You can find other exceptions to the building-up principle in Appendix ...

Catherine Kim 3K

The values of l are 0 and 1 if n = 2. That means the orbital type can only be s or p.

Catherine Kim 3K

No, the value should be given in the formula sheet.

Catherine Kim 3K

Yes! You would use E=hv

Catherine Kim 3K

The atomic absorption spectroscopy part is correct. Yet, the emission line spectrum would be the answer to an experiment where only emitted wavelengths of light are detected.

Catherine Kim 3K

No they will not have the same speed. They will have the same momentum. The formula of the de Broglie wavelength is λ = h/p. P = mass x velocity. An electron is lighter than a proton, so it was have a higher velocity/speed.

Catherine Kim 3K

"Quanta" just means a packet of energy. I believe "quantized" means that the energy is divided into small packets/levels, so it can only have certain discrete values.

Catherine Kim 3K

You could work on the modules on Professor Lavelle's website or the practice questions you worked on with your TA. I believe the format of the test will be short answers.

Catherine Kim 3K

According to the textbook, a black body is an object that absorbs and emits all frequencies of radiation without favor. The object that is heated, or the "hot object," is known as the black body.

Catherine Kim 3K

If you add the mass percentages of each element in a formula together, it usually equals around 100% (does not go over though). Therefore, you can assume 100g of the sample.

Catherine Kim 3K

The syllabus says to make sure to clearly indicate textbook edition, chapter, and homework number.

Catherine Kim 3K

A tip that I use is to first balance the element that occurs the least.

CHEMISTRY COMMUNITY

Search found 31 matches

Re: KBr

Re: Coming up with formula from name

Re: amphoteric substances

Re: Central atom

Re: polarity vs. nonpolarity

Re: Drawing a Dipole

Re: sigma and pi bonds

Re: double bonds vs. single bonds

Re: Electronegativity

Re: Van der Waals

Re: polarizing power

Re: polar vs nonpolar

Re: Formal charge question

Re: Central Atom

Re: Calculating Bond Lengths

Re: Valence electrons

Re: Atomic radius across a period

Re: Trends in first ionization energies

electron configurations

Re: Question 2.43 6th Edition

Re: 1D.25 Seventh Edition

Re: Expected to know?

Re: Energy of photon [ENDORSED]

Re: Atomic Absorption Spectroscopy versus Atomic Emission Spectroscopy

Re: post assessment #29

Re: Meaning of Quanta/Quantized

Re: Test 1 Question

Re: Black Body

Re: Limiting Reactant Steps General Question

Re: Homework Format

Re: Balancing reactions tips