9.2

Question 1

Extrusive Rock

Answer 1

Igneous rock that forms when lava cools above the Earth’s surface

Question 2

Pumice

Answer 2

a pale rock that forms when frothy lava cools in the air. Pumice often floats on water as it is very light and full of holes that once contained gas.

Question 3

Scoria

Answer 3

A dark, igneous rock formed from gassy lava that cools quickly

Question 4

Abrasive

Answer 4

A property of a material or substance that easily scratches another

Question 5

Basalt

Answer 5

A dark, igneous rock with small crystals formed by fast cooling of hot lava. It sometimes has holes that once contained volcanic gases.

Question 6

Obsidian

Answer 6

Ablack, glassy rock that breaks into pieces with smooth shell-like surfaces

Question 7

Igneous Rock

Answer 7

Rocks that form from the cooling of lava or magma as it is thrown through the air from a volcanic eruption

Question 8

Sedimentary Rocks

Answer 8

rocks formed from sediments deposited by water, wind or ice. The sediments are cemented together in layers, under pressure.