9.3

Question 1

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

Answer 1

igneous rocks

Question 2

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

Answer 2

extrusive rocks

Question 3

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.

Answer 3

Pumice

Question 4

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

Answer 4

Scoria

Question 5

a property of a material or substance that easily scratches another

Answer 5

Abrasive

Question 6

igneous rock that forms when magma cools below the Earth’s surface

Answer 6

Intrusive rocks

Question 7

intrusive rock mass that measures more than 100 kilometres across

Answer 7

Batholiths

Question 8

a hard, igneous rock with different-coloured crystals large enough to see. It forms slowly below the Earth’s surface.

Answer 8

Granite

Question 9

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

Answer 9

Basalt

Question 10

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

Answer 10

Obsidian