chemical changes Flashcards
1
Q
What is reduction
A
When a substance is reduced (loses oxygen), it always gains electrons.
2
Q
What is oxidation
A
When a substance is oxidised (gains oxygen), it always loses electrons.
3
Q
A
4
Q
What is oil rig
A
oxidation is loss reduction is gain (of electrons)
5
Q
what happens when a substance is reduced
A
oxygen is lost and electrons are gained
6
Q
what happens when metal reacts with oxygen
A
metal oxides are produced
Calcium + oxygen → calcium oxide
2Ca + O2 → 2CaO
7
Q
what happens with metal oxides losse oxygen
A
return to their atomic form:
Iron oxide + carbon monoxide → iron + carbon dioxide
Fe2O3 + 3CO → 2Fe + 3CO2
8
Q
What charge do ions normally form from metal atoms?
A
positive
9
Q
What name do we give to highly unreactive metals that are found in the Earth’s crust?
A
native metals
10
Q
A
