Atomic Structure and Electron Structure

Question 1

Define Relative Atomic Mass (Ar)

Answer 1

The weighted mean mass of an atom compared with 1/12th of an atom of carbon-12

Question 2

What does m/z mean?

Answer 2

Mass

Question 3

What is the equation for calculating Ar using data from a mass spectrometer?

Answer 3

R.A.M = isotopic mass x % abundance/ 100
Or
R.A.M = isotopic mass x % abundance/total relative abundance

Question 4

What d.p. should Ar always be given to?

Answer 4

1 d.p.

Question 5

What s.f. should the mass of an individual isotope always be rounded to?

Answer 5

A whole number - you cannot have an isotope with a fraction of a neutron or proton

Question 6

Define an atomic orbital

Answer 6

A region within an atom that can hold up to 2 electrons with opposite spins

Question 7

Give the 3D shape of an S orbital and a P orbital

Answer 7

S orbital - spherical
P orbital - dumb-bell

Question 8

Give the order of increasing energy levels

Answer 8

1s
2s
2p
3s
3p
4s
3d
4p

Question 9

How many electrons can each sub level hold?

Answer 9

S - 2
P - 6
D - 10
F - 14

Question 10

How many orbitals are in each sub level

Answer 10

S - 1
P - 3
D - 5
F - 7

Question 11

How do you calculate noble gas configuration from the electronic configuration?

Answer 11

• Write down the electronic configuration of the noble gas that comes before the element
• E.g. [Ar] then numbers you get me

Question 12

What are the two exceptions for the rules of electronic configuration and what is their actual electronic configuration? Why

Answer 12

Chromium (Cr)
1s2 , 2s2 , 2p6 , 3s2 , 3p6 , 4s1 , 3d5
Copper (Cu)
1s2 , 2s2 , 2p6 , 3s2 , 3p6 , 4s1 , 3d10

These structures are of lower energy and represent more stable arrangements

Question 13

Are electrons removed from the 4s or 3d sub shell during the formation of ion?

Answer 13

4s before 3d