Chapter 1 Atomic Structure

Question 1

What is the Z number?

Answer 1

Atomic Number, # of protons

Question 2

What is the A number?

Answer 2

Mass Number, # of protons + # of Neutrons

Question 3

What is the atomic weight?

Answer 3

The weighted average (in amu) of the naturally occurring isotopes of an element.

Question 4

What happens when electrons move from higher energy to lower energy lvl?

Answer 4

They emit the same amount of energy in the form of light

Question 5

What are the four quantum numbers?

Answer 5

n (principal qn - describes shell), period on periodic table ,

l (azimuthal qn - describes subshells), Blocks of periodic table

ml (Magnetic qn),

ms (spin qn)

Question 6

How to calculate l qn?

Answer 6

n-1

Question 7

What is the n+l rule?

Answer 7

The lower the sum of the
values of the first and second quantum numbers, (n + l), the lower the energy
of the subshell.

If two subshells possess the same n + l value, the subshell with the lower n value has a lower energy and will fill with electrons first.

Question 8

How to calculate electron configuration?

Answer 8

1. Start with preceding noble gas.
2. Count down from top of column (1 to 7) starting with S block [Each electron it can hold corresponds to # of columns in each block ( from left to right) S has 2.
3. Continue into f block which has top of column down from 4-5 & 14 e- across.
4. D block whose columns start at 3, end at 6. Holds 10 electrons (left to right).
5. P block columns start at 2 and go 6 e- across

*The electron count is the exponent value

Structure is, Column than block than electron count like 4s^2

Question 9

Lowest subshells?

Answer 9

s is 1s.

p is 2p.

d is 3d.

f is 4f.

Question 10

How is spin labeled?

Answer 10

+1/2 is spin up & -1/2 is spin down

Question 11

Which groups electron configuration has a half filled subshell?

Answer 11

Transition metals. All take electron from s, so will be 4s^1 or 5s^1 and add one to d

Moving the 4s electron up to the 3d-orbital is energetically unfavorable, the extra stability from making the 3d subshell half-filled outweighs that cost.

Question 12

What is a paramagnetic material?

Answer 12

Have unpaired (odd #) electrons that align with magnetic fields, attracting the material to a magnet

Question 13

What is a Diamagnetic material?

Answer 13

Have all paired electrons, which cannot easily be realigned; they are repelled by magnets.

Question 14

Which valence electrons are important for representative elements (those in Groups 1, 2, and 13−18)?

Answer 14

The valence electrons are
found in s- and/or p-orbitals

Question 15

Which valence electrons are important for transition elements?

Answer 15

The valence electrons are found in s- and either d- or f-orbitals.

Question 16

Which block corresponds with which l subshell?

Answer 16

l = 0 → s
l = 1 → p
l = 2 → d
l = 3 → f