Atomic Structure

Question 1

atomic number (Z)

Answer 1

number of protons

Question 2

mass number (A)

Answer 2

protons + neutrons

Question 3

valence electrons

Answer 3

• electrons farthest from the nucleus

- determine reactivity of an atom

Question 4

mole

Answer 4

• unit used to count particles

- represented by avagadro’s number

Question 5

avagadro’s number

Answer 5

6.022 x 10^23 particles

Question 6

isotopes

Answer 6

multiple species of atoms with the same number of protons but different number of neutrons

Question 7

energy value of a quantum

Answer 7

E=hf

-h=6.626 x 10^-34 (planck’s constant)

Question 8

ground state

Answer 8

electrons in its lowest energy state

Question 9

electromagnetic energy of photons emitted when electrons return to ground state

Answer 9

E = hc/lamda =hf

Question 10

Pauli exclusion principle

Answer 10

no 2 electrons in a given atom can possess the same set of 4 quantum numbers

Question 11

principal quantum number (n)

Answer 11

• the larger the integer the higher the energy level

- difference in energy between adjacent cells decreases as the distance from the nucleus increases

Question 12

maximum number of electrons in energy level n (electron shell n)

Answer 12

2n^2

Question 13

azimuthal quantum number (l)

Answer 13

• subshells that occur within each principle energy level
• can be any integer in the range of 0 to n-1
• 4 subshells corresponding to l=0, 1, 2, 3 are s, p, d, f

Question 14

maximum number of electrons that can exist within a subshell

Answer 14

4l + 2

Question 15

magnetic quantum number (ml)

Answer 15

• the particular orbital within a subshell where an electron is highly likely to be found at a given point in time
• all integers from -l to l including 0

Question 16

spin quantum number (ms)

Answer 16

• the spin of a particle
• +1/2 or -1/2
• whenever 2 electrons are in the same orbital they must have different spins

Question 17

(n + l) rule

Answer 17

the lower the values of the sum of the first and second quantum numbers, the lower the energy of the subshell

Question 18

Plancks Theory

the energy wave is:

Answer 18

• directly related to frequency
• indirectly related to wavelength
• directly related to its absorption spectrum
• directly related to its emission spectrum

Question 19

paramagnetic species

Answer 19

• weakly attracted to magnetic field

- unpaired electrons

Question 20

diamagnetic species

Answer 20

• not affected by magnetic field (slightly repelled)

- unpaired electrons

Question 21

comparing atomic radius of molecules with the same number of electrons

Answer 21

the molecule with more protons has a smaller atomic radius because there will be more pull toward the nucleus

Question 22

number of orbitals in a subshell

Answer 22

2l + 1