Periodicity

Question 1

How are elements arranged in the periodic table?

Answer 1

They are arranged in order of increasing atomic number

Question 2

What are groups in the periodic table?

Answer 2

Groups are vertical columns containing elements with similar chemical properties.

Question 3

What are the 3 forms of carbon?

Answer 3

Graphite, diamond and fullerenes

Question 4

What are periods in the periodic table?

Answer 4

Periods are horizontal rows of elements arranged with increasing numbers of outer electrons and move from having metallic characteristics to non-metallic characteristics

Question 5

What are the diatomic elements?

Answer 5

Oxygen, Fluorine, Chlorine, Bromine, Iodine and Nitrogen

Question 6

What is a covalent radius?

Answer 6

A covalent radius is half the distance between the nuclei of 2 atoms that are bonded together

Question 7

What happens to the size of an atom as you go down a group?

Answer 7

The size of the atom increases

Question 8

What happens to the size of an atom as you go across a period from left to right?

Answer 8

The size of the atom decreases

Question 9

What is meant by the first ionisation energy

Answer 9

It’s the energy required to remove one outer electron from every atom in one mole of free atoms

Question 10

What is the meant by the second ionisation energy?

Answer 10

It’s the energy required to remove one outer electron from every atom in one mole of free atoms where one electron has already been lost.

Question 11

What is the equation for the first ionisation energy of magnesium?

Answer 11

Mg(g) -> F+(g) + e-

Question 12

How does phosphorus exist?

Answer 12

P4

Question 13

How does sulphur exist?

Answer 13

S8

Question 14

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

Answer 14

The ionisation energy increases across a period because the increasing nuclear charge results in the electrons being pulled closer to the nucleus making them held more tightly.

Question 15

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

Answer 15

The ionisation energy decreases as you go down a group because the number of electron energy levels is increasing meaning that the electrons are further from the nucleus. There is also increased shielding.

Question 16

What is electronegativity?

Answer 16

It’s the measure of attraction an atom involved in a covalent bond has for the electrons in the bond.

Question 17

What happens to the electronegativity as you go across a period from left to right?

Answer 17

The electronegativity increases because the nucleus is increasing in positive charge and so the attraction for the shared electrons is increasing.

Question 18

What happens to the electronegativity as you go down a group?

Answer 18

The electronegativity decreases as you go down a group because the number of electron energy levels is increased meaning that the shared outer electrons are further from the nucleus and the shielding increases.