The atmosphere

Question 1

The earths first atmosphere was formed by gases produced from_______

Answer 1

volcanos

Question 2

What was the temp of earth?

Answer 2

very hot no oceans

as cooled water vapour condensed to form liquid water-oceans

Question 3

Sate why scientists can t be certain about composition of early atmosphere

Answer 3

no humans around to measure

have to use clues-diff sources not all lead to same conclusion

Question 4

Name the 3 phases of earth

Answer 4

volcanoes gave out steam and CO(2)
Green plants evolved and produced oxygen
Ozone layer allows evolution of complex animals

Question 5

Test for oxygen

Answer 5

using glowing splint

relight glowing splint

Question 6

name 2 main gases in atmosphere today

Answer 6

nitrogen and oxygen

Question 7

describe link between limestone in earths crust and and carbon dioxide overime

Answer 7

CO(2)mostly made up of it at beginning
now only 0.04%
some dissolved in oceans
marine organisms use this to make calcium carbonate for shells
die sink to sea bed eventually form limestone

Question 8

State how human activity affects the atmosphere today and one natural cause

Answer 8

deforestation-CO(2)burning trees,fewer trees to remove CO(2) from atmosphere
Burning fossil fuels-releases CO(2)into atmosphere Sulfur dioxide burning coal
farming -cattle’s and rice fields release methane