Periodicity

Question 1

What is periodicity?

Answer 1

Repeating trends of physical or chemical properties

Question 2

What happens to the atomic radius as you go down a group?

Answer 2

The atomic radius increases
There is an increase in number of principal energy levels
Increase in shielding
Outer Electron is further from the nucleus

Question 3

What happens to the atomic radius as you go across a period?

Answer 3

Number of protons increases
Shielding is constant
Electrons are more strongly attracted to the nucleus and atomic radius decreases

Question 4

What is the first ionisation energy?

Answer 4

The energy required for the removal of 1 mol of electrons from 1 mol of gaseous atoms

Question 5

What happens to the ionisation energy as you go down a group?

Answer 5

Ionisation energy decreases
The electron is removed from a higher principal energy level
The electron is further from the nucleus
There is more shielding
Weaker attraction between nucleus and outer electron

Question 6

What happens to the ionisation energy as you go across a period?

Answer 6

Ionisation energy increases
The number of protons increases
Shielding is constant
Stronger attraction between nucleus and outer electron

Question 7

What happens to the 1st IE of a group 3 element

Answer 7

Ionisation energy decreases
The electron is removed from a higher energy p sub-level
Weaker attraction between nucleus and outer electron

Question 8

What happens to the 1st IE of a group 6 element

Answer 8

Ionisation energy decreases
There is a pair of electrons in a p orbital
Extra repulsion means less energy is required to remove the electron

Question 9

What happens to successive ionisation energies?

Answer 9

Successive ionisation energy increases
The positive charge on the ion increases
The ionic radius decreases
Nuclear attraction on the outer electron increases

Question 10

What is a metallic bond

Answer 10

A strong electrostatic attraction between the positive ions and delocalised electrons

Question 11

What are the factors that affect the strength of a metallic bond and how does the metallic bond get stronger

Answer 11

The ionic charge on the metal (higher)
The number of delocalised electrons (more)
The ionic radius (smaller)

Question 12

Stronger metallic bonds = ?

Answer 12

Higher M.P. / B.P.

Question 13

What are some properties of emtals

Answer 13

Good conductors electricity and heat (delocalised electrons free to move and flow)
High M.P. and B.P. (strong electrostatic attraction…)
Malleable and ductile (layers of ions sliding over each other)

Question 14

Metallic bonding comparison script

Answer 14

Size of the ion is smaller / decreases
The charge of the ion is higher / increases
More delocalised electrons
Stronger electrostatic attraction between the positive ions and delocalised electrons

Question 15

What are ionic bonds

Answer 15

Strong electrostatic forces of attraction between oppositely charged ions

Question 16

Name the 2 giant covalent elements

Answer 16

Carbon
Silicon

Question 17

Comparing the M.P. / B.P. of substances script

Answer 17

Bonding, Crystal Structure, IMFs? Strongest IMF?
Name the type of attraction being broken and relative strength
Compare the melting/boiling points

Question 18

All molecules have London forces, what to say about em?

Answer 18

larger molecule –> more electrons –> stronger London forces –> requiring more energy to break

Question 19

Some have permanent dipole-dipole if they are polar, how to know if they are polar?

Answer 19

Has the molecule got different atoms arounds the central atom?
Has the central atom got lone pairs?

Question 20

How do hydrogen bonds work

Answer 20

When hydrogen atoms bond directly to O, N or F