Grade 9 - Types of Explosions

Liquid nitrogen boils at which temperature?

• -256 ⁰ C

• -196 ⁰ C

• -87 ⁰ C

What caused the explosion in the picture?

• increased pressure

• increased the volume of container

• decreasing the volume of container

The explosion caused by liquid nitrogen in a trashcan is an example of a physical change. Why?

• because nitrogen is a gas.

• because new substances are formed.

• because no new substances are formed.

Which one of the following explosions are caused by physical changes?

• explosion caused by mixing vinegar and baking soda.

• volcano eruption

• explosion caused by leaking petrol tank.

Which one of the following is an example of a physical change?

• burning coal.

• frying an egg.

• heating solid wax until it changes to a liquid.

Which one of the following sentence is true for chemical change?

• No new substances are made.

• pressure is increased in the process.

• atoms in reactants rearrange to form products.

Which one of the following is an example of a chemical change?

• rusting of a metal.

• slicing bread.

• ice cube melting into water.

How can you increase pressure in gases?

• increase the gas particles in a container.

• decrease the size of container.

• increase the temperature.

• all the above.

Why decreasing the size of the container increases the pressure in gases?

• so the particles will move faster.

• so more particles hit the surface.

• so particles hit a surface more often.

Why increasing the temperature also increases the pressure in gas?

• because the particles move faster.

• because the particles hit more often.

• because he particles hit with more force.

• all the above.