C3.1

Question 1

How to find the formulae of non metals in group 0 (the noble gases)

Answer 1

The formula = the chemical symbol
Eg, Heliums formulae = He

Question 2

How to find the formulae of group 7 / 17 non metals

Answer 2

Group 7 formulae = chemical symbol ₂
So chlorine = Cl ₂

Question 3

Atoms which naturally form with 2 of themselves are called

Answer 3

diatomic particles, most diatomic particles are found in group 7

Question 4

Other diatomic particles include

Answer 4

• oxygen
• nitrogen
• hydrogen

Question 5

Phosphorus

Answer 5

Exists as simple covalent molecules with 4 phosphorus atoms, so it’s written as P₄

Question 6

All other non metals

Answer 6

Exist as giant structures, meaning that the number of particles cannot be counted
Their formula is their chemical symbol.

Question 7

Sulphur

Answer 7

Exists as a simple molecules (not a giant structure) of 8 atoms.

Question 8

Metals formulae

Answer 8

Exist as giant metallic lattices
Formula = empirical formula (chemical symbol)

Question 9

Name of simple covalent compounds

Answer 9

Formed from 2 Or more non metals
Simple molecules consisting of a fixed number of different atoms covalently bonded
Eg hydrogen chloride

Question 10

The formulae of simple covalent molecules show

Answer 10

• each element in the molecule
• number of each atoms in the molecule
  Eg hydrogen chloride = HCl

Question 11

Formula of giant covalent compounds

Answer 11

formed from two or more nonmetals
Giant lattice of covalently bonded atoms
Eg Diamond = C

Question 12

How to write the formula of giant covalent compounds

Answer 12

• write the ratio of the numbers of each atom (empirical formula)
• eg, silicon dioxide = SiO₂

Question 13

How to write formulae of non metals

Answer 13

• for the noble gases you use the chemical symbol of the element
• for group 7, you use the chemical symbol with a subscript two
• for phosphorus it’s P with subscript four
• for all other nonmetals they exist as giant structures and their formula is also the chemical symbol
• there is one exception, sulphur exist as a simple molecule of eight atoms. It is written as S subscript eight.
• Metals exist as giant metallic lattices, and the formula is their empirical formula (their chemical symbol)
  -for simple covalent compounds you write each element in the molecule and the number of each element that is found there
• giant covalent latices are more rare but you use the empirical formula to write their formulae

Question 14

Hydrogen ions formulae

Answer 14

NORMALLY have a plus on charge
H⁺

Question 15

Metal ions have

Answer 15

• positive charge
• their charges are the same as the group number (column) that they are in
• eg group three has +3 charge

Question 16

Transition metal (groups 3-12) ions have

Answer 16

• positive ions
• usually a plus two charge
• SOMETIMES can form an ion with a different charge
• silver ALWAYS has has 1+ charge
• Iron is ALWAYS EITHER 2+ or 3+ charge

Question 17

Non metals charge

Answer 17

Form negative ions
- their charge is 8-(group number)
For example, an element in group 7 would have 1+, because 8-7 is one

Question 18

How to name compound ions

Answer 18

Positive ions - name of element with +
Lithium = Lithium ion

Negative ions = take the first part of the element and add ide
Chlorine ion = chloride

Question 19

Negative compounds that contain oxygen formula?

Answer 19

First part of non oxygen element + ate

Exception = hydroxide (OH-)

Question 20

Naming ionic compounds

Answer 20

1st part of name = positive ion
2nd part of name = negative ion
Roman numeral if nessacary
The Roman numeral shows the charge if it’s a transition metsl