Ionic, covalent and metallic structures. *

Question 1

What is an ion?

Answer 1

an atom or group of atoms with an electrical charge

Question 2

How are ions formed? (4 points)

Key words:

atoms, outer shell, electrons. unequal, charge, metal, non-metal

Answer 2

• atoms with incomplete outer shells either lose or gain electrons
• the atom then has an unequal number of protons and electrons
• this means it has an overall charge
• one atom must be metal, and one must be non-metal

Question 3

What charge will an atom that loses electrons have?

Answer 3

if it loses electrons, it will have more protons than electrons, giving it a positive charge

Question 4

What charge will an atom that gains electrons have?

Answer 4

if it gains electrons, it will have more electrons than protons, giving it a negative charge

Question 5

What charge will an atom that gains electrons have?

Answer 5

if it gains electrons, it will have more electrons than protons, giving it a negative charge

Question 6

What does the group number show about the atom?

Answer 6

the number of electrons in the outer shell

Question 7

Do groups 1-3 lose or gain electrons?

Answer 7

lose

Question 8

Do groups 5-7 lose or gain electrons?

Answer 8

gain

Question 9

Do metal atoms lose or gain electrons?
What charge will they have?

Answer 9

metal atoms lose electrons
they have a positive charge

Question 10

Do non-metal atoms lose or gain electrons?
What charge will they have?

Answer 10

non-metal atoms gain electrons
they have a negative charge

Question 11

What is a compound ion?

Answer 11

an ion made up of a group of atoms

Question 12

Name five compound ions and give their formulae

Answer 12

• hydroxide = OH -
• sulfate = SO4 2-
• nitrate = NO3 -
• carbonate = CO3 2-
  ammonium = NH4 +

Question 13

What must an ion drawing always have?

Answer 13

• square brackets around the outside
• a + or - outside the brackets

Question 14

What is an ionic bond?

Answer 14

an ionic bond is the electrostatic force of attraction between oppositely charged electrostatic ions

Question 15

Ionic compounds:

Fill the gaps:

the formation of an _____ ____ involves the transfer of _________ from the _____ to the ___-_____

Answer 15

the formation of an ionic bond involves the transfer of electrons from the metal to the non-metal

Question 16

Ionic formulae:

Fill the gaps:

the ratio of _____ to ___-_____ ions is the amount of ________ ____ or ______

some ionic __________ contain __________ ions so ________ are used

Answer 16

the ratio of metal to non-metal ions is the amount of electrons lost or gained

e.g KCl has a 1:1 ratio as its K+ and Cl- so it balances out

e.g. K2O has a 2:1 ratio as its K+ and O2- so 2 K ions are needed to balance the charge

some ionic compounds contain compound ions so brackets are used

e.g. calcium nitrate = Ca(NO3)2 which shows you have 1 Ca2+ and 2 NO3 ions

Question 17

What is oxidation?

Answer 17

oxidation is losing electrons

Question 18

What is reduction?

Answer 18

reduction is gaining electrons

Question 19

Give three properties of ionic compounds

Answer 19

• conducts electricity when molten - the ions are free to move and carry a charge
• high melting and boiling point - giant lattice structure which requires a lot of energy to break
• soluble in water - attracted to the water molecules which carry a small electrostatic charge

Question 20

What kind of structure do ions have?

Answer 20

ions have a giant ionic lattice structure
the lattice is formed because the ions attract each other and form a regular pattern with oppositely charged ions next to each other

Question 21

What is covalent bonding?

Answer 21

a shared pair of electrons between 2 atoms

Question 22

Which type of element can form covalent bonds? (metal/non-metal)

Answer 22

non-metal

Question 23

How does covalent bonding happen? (4 points)

Key words:

non-metal atoms, pair of electrons, molecule, covalently bonded element, covalently bonded compound

Answer 23

• when two non-metal atoms overlap they share a pair of electrons
• this forms a molecule
• if the atoms are all the same type then it forms a covalently bonded element
• if the atoms are different then it forms a covalently bonded compound

Question 24

What does the number of electrons on the outer shell show?

Answer 24

how many covalent bonds an element will form

Question 25

What are intermolecular forces?

Answer 25

the attractions between molecules

Question 26

What is a simple molecular structure?

Answer 26

a substance made of millions of weakly attracted small molecules

Question 27

What is a giant molecular structure?

Answer 27

a lattice structure that is held together by strong covalent bonds, with no intermolecular forces

Question 28

Give two examples of a giant covalent structure

Answer 28

diamond and graphite

Question 29

What is an allotrope?

Answer 29

different physical forms of the same element

Question 30

What are diamond and graphite both made up of?

Answer 30

lattice carbon atoms going in all directions

Question 31

Give two points about diamonds structure

Answer 31

• has a 3D structure
• each carbon atom has strong covalent bonds with other atoms

Question 32

Give four points about graphites structure

Answer 32

• each carbon atom has made covalent bonds with three other atoms on the same layer
• has a layered structure - atoms in the same layer are bonded by strong covalent bonds
• each layer is a giant covalent structure
• the layers are held together by weak intermolecular forces

Question 33

Does diamond insulate or conduct electricity?

Answer 33

diamond is an electrical insulator

Question 34

Does graphite insulate or conduct electricity?

Answer 34

graphite conducts electricity

Question 35

What kind of structure do metals have?

Answer 35

a giant crystalline structure

Question 36

What is metallic bonding?

Answer 36

strong electrostatic attractions between positive metal ions and sea of delocalised electrons