Expansion and Contraction of Materials

What happens to most materials when they are heated?

• They shrink

• They melt immediately

• They expand

• They disappear

When materials cool down, they usually...

• Become heavier

• Expand

• Catch fire

• Contract

Which one of the following expands the most when heated?

• Solid

• Liquid

• Gas

• Rock

What is the meaning of "expand"?

• To become longer, wider, or bigger

• To change color

• To melt

• To become solid

What is used in railway tracks to prevent damage due to expansion?

• Glue

• Expansion gaps

• Water

• Paint

Why do metal lids on jars become easier to open after being heated?

• They freeze

• They melt

• They expand

• They break

Which of the following is an example of expansion and contraction in everyday life?

• A balloon flying

• A metal bridge with gaps between sections

• A kite flying

• Water turning into steam

Why do telephone wires sag more in hot weather?

• Because they break

• Because they expand

• Because they freeze

• Because they become lighter

What can happen if there is no space for expansion in metal structures?

• Nothing happens

• The structure may bend or break

• The structure becomes soft

• The color changes

What is contraction?

• When a material gets bigger

• When a material changes color

• When a material becomes smaller due to cooling

• When a material becomes lighter