Changes in Earth’s atmosphere by Raja Ahmed https://padlet.com/16rahmed/ointyduq2meehx9j Chemistry GCSE 2-10-2020 en-us 2020-10-02 07:51:52 UTC 2020-10-02 08:37:59 UTC hello@padlet.com Volcanoes 16rahmed https://padlet.com/16rahmed/ointyduq2meehx9j/wish/797049976 A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. Volcanoes released carbon dioxide water vapour and nitrogen in earth’s atmosphere
Reason:
 It is believed that there was intense volcanic activity for the 4500 millions years ago of the Earth's existence.]]> 2020-10-02 07:55:51 UTC https://padlet.com/16rahmed/ointyduq2meehx9j/wish/797049976 Early Atmosphere 16rahmed https://padlet.com/16rahmed/ointyduq2meehx9j/wish/797053049 Earths Atmosphere was mainly Carbon Dioxide .
Reason:
Nitrogen released from volcanoes gradually build up the atmosphere with small proportion of ammonia and methane
Also because there was little to no life at that time so oxygen wasn’t required

]]> 2020-10-02 07:59:19 UTC https://padlet.com/16rahmed/ointyduq2meehx9j/wish/797053049 First sign of life 16rahmed https://padlet.com/16rahmed/ointyduq2meehx9j/wish/797054829 The age of the Earth is about 4.54 billion years; the earliest undisputed evidence of life on Earth dates from at least 3.5 billion years ago. The first organism which came to life which didn’t required oxygen so they survived. 
Example is Algae]]> 2020-10-02 08:01:35 UTC https://padlet.com/16rahmed/ointyduq2meehx9j/wish/797054829 Formation of Algae 16rahmed https://padlet.com/16rahmed/ointyduq2meehx9j/wish/797056474 2.4 billion years ago, algae formed which photosynthesised and released Oxygen as waste product. These were single cell organisms.
These microbes didn’t required oxygen to survive but they produced it through photosynthesis. This caused their population to grow... ]]> 2020-10-02 08:03:41 UTC https://padlet.com/16rahmed/ointyduq2meehx9j/wish/797056474 Oxygen level increased 16rahmed https://padlet.com/16rahmed/ointyduq2meehx9j/wish/797058002 ...thus, the oxygen level increased in the atmosphere giving chance to plants and animals to evolve. ]]> 2020-10-02 08:05:32 UTC https://padlet.com/16rahmed/ointyduq2meehx9j/wish/797058002 Carbon level dropped 16rahmed https://padlet.com/16rahmed/ointyduq2meehx9j/wish/797059083 This way carbon became trapped which lead to a reduced amount of Carbon Dioxide proportion in the atmosphere
Reasons:
it was locked up in sedimentary rocks (such as limestone) and in fossil fuels
it was absorbed by plants for photosynthesis
it dissolved in the oceans
]]> 2020-10-02 08:06:54 UTC https://padlet.com/16rahmed/ointyduq2meehx9j/wish/797059083 Beginning of the Oceans 16rahmed https://padlet.com/16rahmed/ointyduq2meehx9j/wish/797061545 As the Earth cooled down water vapour condensed to form what is known as The Ocean today
Temperature of started to cool down. 
As the "magma ocean" of the planetary surface cooled, it began to form a thin, hot crust. ... The crustal heat was convected upwards through the thick atmosphere and radiated to space, so that Earth continued to cool relatively quickly at first, then more slowly as the crust cooled and thickened.]]> 2020-10-02 08:09:51 UTC https://padlet.com/16rahmed/ointyduq2meehx9j/wish/797061545 Today 16rahmed https://padlet.com/16rahmed/ointyduq2meehx9j/wish/797062782 Today’s atmosphere is made up of Nitrogen and Oxygen with little Carbon Dioxide as today many living organism require oxygen to survive.]]> 2020-10-02 08:11:12 UTC https://padlet.com/16rahmed/ointyduq2meehx9j/wish/797062782