Unit 1: Atomic Structure And Properties

Question 1

How to compute the number of molecules or atoms in a given mass: n = ?

Answer 1

m / M, m = mass, M = Molar Mass

Question 2

Mass Spectrum? (3•)

Answer 2

•X axis: Mass/Charge Ratio
•Y axis: relative number of atoms

• ^(X) (element) with a relative abundance of (Y)%

Question 3

Law of definite proportions?

Answer 3

Ratios that compare the absolute abundance of two atoms.

Question 4

!!!Imperial formula?

Answer 4

The lowest proportions of molecules with the same ratios between two atoms.

Question 5

Force between two charged particles: F_coulombic oc ?

Answer 5

(q_1 q_2) / r^2, q = charge (coulombs), r = distance between the two particles

Question 6

1 coulomb = ?

Answer 6

6 * 10 ^ 18 electrons

Question 7

Photoelectron spectroscopy (PES)? (2•)

Answer 7

•X axis: energy increases
•Y axis: the amount of energy required to remove an electron from an atom at a different shell

Question 8

Graph of potential energy vs distance between atoms? 2•

Answer 8

•X axis: distance (r) between two atoms
•Y axis: potential energy

Question 9

Interstitial alloys?

Answer 9

Created by atoms of different radii where the smaller (non-metallic) atoms fill the spaces inside the electron cloud.

Question 10

Substitutions alloys?

Answer 10

When atoms of comparable radii have an atom that substitutes for the other in the lattice.

Question 11

!!!!!!!!!!Can you justify a Coulomb’s law answer with comparing numerators and denominators??

Question 12

Shells/energy level?

Answer 12

Electron homes that can reside in a subshell/sublevel

Question 13

Subshell/sublevel?

Answer 13

Configure on the greatest probability of finding an electron in an energy level.

Question 14

Photoelectron spectroscopy (PES)?

Answer 14

photoelectron spectrophotometers use high energy radiation to remove an electron from an atom. This can be used to experimentally determine the relative energies of electrons in atoms or ions.

Question 15

Hund’s rule?

Answer 15

Each orbital must be filled with one electron before all orbitals being occupied with one, and then each orbital can be filled with a second.

Question 16

Pauli exclusion principle?

Answer 16

No two electrons can have the same four quantum numbers.

Question 17

Quantum numbers of electrons? 4•

Answer 17

•principle quantum number (n, starting from 1 and any integer): the energy level of where the electron is.

•azimuthal quantum number (l, either 0 to 1 less than n): sublevel of the electron and the shape of the sublevel

•magnetic quantum number (m_l, integer including 0 = -l to l): orientation of the orbital in space

•spin quantum number (m_s, either 1/2 or -1/2): 1/2 = spin up, -1/2 = spin down

Question 18

Rules of Lewis structures?

Answer 18

•valence electrons of all atoms are added together
•if substance is polyatomic ion, we must take into account the electrons used to form ion (e.g., if -1 charge, we must draw the extra electron)
•pair of electrons placed between each two atoms in skeletal structure represent a covalent bond. These are called bonding pairs.
•remaining electrons are used to complete octet of all outer atoms in skeleton. They are called non bonding pairs (aka lone pairs) of electrons.
•left over electrons are added in pairs to the central atom. They are nonbonding pairs or lone pairs as well
•when all electrons have been placed, the outer atoms will all have outlets. The central atom may have octet, or it may have more or fewer than eight electrons

Question 19

Octet rule?

Answer 19

When noble gas has been achieved by eight electrons around the atom.

Question 20

Halogens?

Answer 20

Anions with a -1 charge

Question 21

Every covalent bonds include what type of bond?

Answer 21

Sigma bonds

Question 22

pi bonds?

Answer 22

Clouds are more spread that allows overlap within double+ bonds.