Earth - Science; New

Question 1

Element

Answer 1

An element is a pure substance made up of only one type of atom.

Question 2

Mineral

Answer 2

A mineral is a naturally occurring, solid and inorganic substance made up of elements.

Question 3

Rocks

Answer 3

Rocks are made up of two or more minerals

Question 4

Colour

Answer 4

The different minerals which make up a rocks give them their colours and patterns. Colour is not a reliable method for identification because the same type of rock can be different colours.

Question 5

Hardness

Answer 5

The property of a substance to resist scratching or denting

Question 6

Lustre

Answer 6

This is how shiny a mineral is. We describe lustre with terms like metallic (like a shiny coin), and earthy (like dirt).

Question 7

Streak

Answer 7

This is the colour of the mineral when crushed into a powder, or when the mineral is scratched against a tile. Often the colour of the streak is different from the main colour of the mineral.

Question 8

Cleavage

Answer 8

The way a crystal naturally breaks along a line

Question 9

why do porous igneous rocks have air bubbles in them?

Answer 9

due to gas bubbles that were trapped in the rock when the lava was rapidly cooling. Porous igneous rocks are always extrusive igneous rocks.

Question 10

What is recrystallisation

Answer 10

When the rock is molten the elements can move around, and new minerals form in this process. Recrystallisation occurs when new crystals grow as the rock cools down.

Question 11

What is Foliation

Answer 11

Pressure causes the minerals to become squashed, flat, or form into long needle shapes. The rock then develops layers or bands in a process called foliation.