Material Changes

In a chemical change, new substances are formed, for example

• heating glass and bending it

• melting an ice

• burning of wood

• boil water

iron + sulfur --> iron sulfide

from that word equation, the reactant(s) is/are ....

• iron

• iron and sulfur

• sulfur

• iron sulfide

when something burns, it reacts with the .... in the air

• CO₂

• CO

• C

• O₂

What happens in a chemical reaction?

• Atoms form new combinations

• Atoms do not form new combinations

In detecting chemical reactions, there are few clues we can look, except ...

• A colour change

• Heat is produced

• A gas is given off

• No new substances

. ........ is formed when iron reacts with oxygen in the air

• iroxy

• rust

• crumble

• substances

from this experiment, we can conclude that rusting need

• oxygen

• oil

• water

• oxygen and water

how can iron be protected?

• by painting it

• by drowning it

• by blowing it

• by throwing it

The chemical symbol for magnesium is

• Mg

• MG

• mg

• Mag

The compound formed when magnesium reacts with oxygen is

• Magnesium oxide

• Magnesiumide

• Magnesium oxygen

• Oxymagnesium