Chem

Question 1

Mass number

Answer 1

The sum of protons and neutrons

Question 2

Atomic weight

Answer 2

The weighted average of different isotopes reported on the periodic table

Question 3

Equation for energy of a quantum

Answer 3

E=hf; E=hc/λ; E=hv/λ

*Positive E corresponds to emission, negative E corresponds to absorption

Question 4

Equation for angular momentum

Answer 4

L=mvr

Question 5

Equation for angular momentum of a hydrogen electron

Answer 5

L=nh/2π

Question 6

Equation for energy of an electron

Answer 6

E= -R(H)/n^2
R(H)=2.18*10^-18 J/electron
*Energy (E) is directly proportional to principal quantum number (n)

Question 7

Speed of light, c

Answer 7

3*10^8 m/s

Question 8

Atomic number

Answer 8

Number of protons

Question 9

Planck’s constant

Answer 9

h=6.626*10^-34 Js

Question 10

Lyman series

Answer 10

The group of hydrogen emission lines corresponding to transitions from energy levels n≥2 to n=1

Question 11

Balmer series

Answer 11

The group of hydrogen emission lines corresponding to transitions from energy levels n≥3 to n=2

Question 12

Paschen series

Answer 12

The group of hydrogen emission lines corresponding to transitions from energy levels n≥4 to n=3

Question 13

Heisenberg uncertainty principle

Answer 13

It is impossible to simultaneously determine, with perfect accuracy, the momentum and the position of an electron

Question 14

Pauli exclusion principle

Answer 14

No two electrons in a given atom can possess the same set of four quantum numbers

Question 15

Principle quantum number (n)

Answer 15

The larger the integer value of n, the higher the energy level and radius of the electron’s shell
*Also tells you the possible number of subshells (l)

Question 16

Maximum number of electrons within a shell

Answer 16

2n^2

Question 17

Equation for energy of a quantum

Answer 17

E= -R(H)*[(1/ni^2)-(1/nf^2)]
*The difference in energy between two shells decreases as the distance from the nucleus increases because the energy difference is a function of [(1/ni^2)-(1/nf^2)]

Question 18

Azimuthal quantum number (second quantum number, l)

Answer 18

Shape and number of subshells within a given principal energy level (shell)
*For any [rincipal quantum number (n), there will be n possible values for l, ranging from 0 to (n-1)

Question 19

Maximum number of electrons within a subshell

Answer 19

4l+2

l= Number of subshells

Question 20

Magnetic quantum number [third quantum number, m(l)]

Answer 20

Specifies the particular orbital within a subshell where an electron is most likely to be found at a given moment in time
*Possible values range from (-l to +l) where l= the number of subshells

Question 21

Spin quantum number [fourth quantum number, m(s)]

Answer 21

Refers to the two spin orientations that apply to an electron, +1/2 and -1/2
*Two electrons in the same orbital must have opposite spins

Question 22

Aufbau principle (building-up principle)

Answer 22

Each subshell will fill completely before electrons begin to enter the next one

Question 23

n+1 rule

Answer 23

The lower the sum of the values of the first and second quantum numbers, n+1, the lower the energy of the subshell
*Used to rank subshells by increasing energy
*If two subshells possess the same n+1 value, the subshell with the lower n value has a lower energy and will fill the electrons first
Example: For 5d, n=5 and l=2, so n+1=7. For 6s, n=6 and l=0, so n+1=6. Therefore, the 6s subshell has lower energy and will fill first

Question 24

Hund’s rule

Answer 24

Within a given subshell, orbitals are filled such that there are a maximum number of half-filled orbitals with parallel spins, based on electron repulsion
*Half-filled and fully filled orbitals have lower energies (higher stabilities) than other states

Question 25

Exceptions to electron configuration

Answer 25

``` 1). Group 6 elements Example: Chromium [Ar]4s1 3d5 2). Group 11 elements Example: Copper [Ar]4s1 3d10 *move an s electron to d subshell so its half-filled or fully filled ```

Question 26

Paramagnetic

Answer 26

Magnetic field will cause parallel spins in unpaired electrons and therefore causes an attraction

Question 27

Diamagnetic

Answer 27

Materials consisting of atoms that have only paired electrons will be slightly repelled

Question 28

Metal characteristics

Answer 28

``` Lustrous (shiny) Solid (except mercury) High melting point High densities (except lithium) Malleable Ductility- ability to be drawn into wires Low effective nuclear charge Low electronegativity Large atomic radius Small ionic radius Low ionization energy Low electron affinity Good conductors of heat and electricity ```

Question 29

Nonmetal characteristics

Answer 29

``` Brittle in the solid state Little to no metallic luster High ionization energies High electron affinities High electronegativities Small atomic radii Large ionic radii Poor conductors of heat and electricity ```

Question 30

Metalloid characteristics

Answer 30

electronegativities lie between metals and nonmetals Ionization energies lie between metals and nonmetals Varied densities, melting points, and boiling points Good semiconductors