year 8 geology - rocks & minerals

Question 1

igneous rock

Answer 1

igneous rock is formed when magma or lava are cooled

Question 2

metamorphic rock

Answer 2

if you put a sedimentary rock under heat and pressure

Question 3

sedimentary rock

Answer 3

when sediments are placed under pressure or compacted

Question 4

weathering

Answer 4

the disintegration and decomposition of rocks

Question 5

physical weathering

Answer 5

causes rocks to disintegrate (smaller pieces)

Question 6

chemical weathering

Answer 6

causes rock to decompose (change chemicals)

Question 7

biological weathering

Answer 7

caused by plants and animals and its actions speed up mechanical and/or chemical weathering

Question 8

exfoliation

Answer 8

repeated heating and cooling of rock can cause cracks to form

Question 9

abrasion

Answer 9

the breaking away of rock by colliding particles

Question 10

freeze thaw weathering

Answer 10

when water freezes it expands, taking up space

Question 11

carbonation weathering

Answer 11

the mixing of water with CO2 from the air to make carbonic acid or acid rain

Question 12

oxidation weathering

Answer 12

oxidation is a chemical reaction between some minerals in rock and the oxygen in the air (causes a colour change)

Question 13

erosion

Answer 13

erosion is the transportation of sediments from weathering by water, wind, ice or gravity

Question 14

water erosion

Answer 14

the transport of sediments by water from one location to another

Question 15

wind erosion

Answer 15

the transport of sediments by wind from one location to another

Question 16

ice erosion

Answer 16

the transport of sediments by ice from one location to another

Question 17

gravity erosion

Answer 17

the transport of sediments by gravity from one location to another

Question 18

horizontal axis

Answer 18

thing you change

Question 19

vertical axis

Answer 19

thing you measure

Question 20

rock cycle

Answer 20

volcanic eruption > igneous rock > sediment > sedimentary rock > metamorphic rock > magma

Question 21

age of rock

Answer 21

relative age - where rock layers are compare and rocks found lower are older
actual age - using radioactive dating fossils to date rock

Question 22

types of igneous rock

Answer 22

extrusive - forms when lava cools in the surface of the earth
intrusive - forms when below the surface of the earth