p5. chemistry in the atmosphere Flashcards
(20 cards)
name proportions of different gases in the atmosphere - earth
- 4/5 of nitrogen ( 80 % )
- 1/5 of oxygen ( 20 % )
- small proportions of other gases like :
~ carbon dioxide
~ water vapour
~ noble gases
theory - where did the atmosphere come from
- intense volcanic activity
- released gas from early atmosphere = similar to mars and venus’ atmosphere
- they have :
~large amount of carbon dioxide
~ little or no oxygen
~ small amounts of other gases = ammonia, methane - also released water vapour = condensed as the earth cooled to form oceans
describe the modern atmosphere
- approximately 200 million years - proportions of different gases have been relatively stable
- 80% nitrogen
- 20% oxygen
- other gases - carbon dioxide,water vapour and noble gases
what produced oxygen for the atmosphere today and how
- algae and plants by photosynthesis
- carbon dioxide + water = glucose + oxygen
- algae produced around 2.7 billion years ago and then oxygen was produced
- plants then evolved and % of oxygen increased to the level where animals could evolve
how did carbon dioxide decrease
- algae and plants due to photosynthesis
- carbon dioxide decreased formation of sedimentary rocks and fossils which contained carbon
formation of :
limestone
coal
crude oil
natural gas
- limestone = layers of limey deposits build up on ocean floor and compacted over weight of water
- coal = from trees in dense forests in low-lying wetland areas
~ flooding caused wood from forests to be buried where oxidation couldn’t take place
~ compression and heating over years turns wood into coal - crude oil = ancient biomass ( plankton )
- natural gas = layers of decomposing plants and animals are subject to intense heat from earth and pressure of rocks
purpose of greenhouse gases
- give examples
- maintain temperature on earth high enough to support life
- water vapour.carbon dioxide.methane
how does the greenhouse effect work
- electromagnetic radiation at most wavelengths passes through the Earth’s atmosphere
- Earth absorbs most of the radiation and warms up
- Earth radiates energy as infrared radiation
- some of the infrared radiation goes into space
- some of the infrared radiation is absorbed by greenhouse gases in the atmosphere
- the lower atmosphere warms up
human activities that increase greenhouse gases in atmosphere
- burning fossil fuels in vehicles and power stations releases carbon dioxide
- deforestation releases carbon dioxide and reduces absorption of carbon dioxide through photosynthesis
four effects of global climate change
- glaciers and polar ice melting
- sea levels rising
- patterns of rainfall changing ,producing floods or droughts
- habitats changing
what is carbon footprint
- total amount of carbon dioxide ( and other greenhouse gases ) which are emitted over the full cycle of a product,service or event
how to reduce carbon footprint
- reducing emissions of carbon dioxide and methane
give examples on reducing carbon footprint
- reduce,reuse,recycle
- reduce electricity usage
- reuse bottles and bags
- recycle plastic
how is carbon monoxide produced
- incomplete combustion of any fuel containing carbon atoms
how is soot ( carbon particles ) produced
- incomplete combustion of any fuel containing carbon atoms
how is sulfer dioxide produced
- combustion of fossil fuels which contain sulfer impurities
how is nitrogen oxide produced
- oxidation of atmospheric nitrogen inside engine of car,lorry,truck etc
describe carbon monoxide
- toxic gas
- colourless and odourless
- hard to detect
causes of sulfur dioxide and oxides of nitrogen
- causes respiratory problems
- causes acid rain
problems with pullutants in the air
- sulfur dioxide
- oxides of nitrogen
- sulfur dioxide = acid rain which causes harm and kills plants and animals
~ damages man made objects - infastructure - oxides of nitrogen = acid rain
~ react with other pollutants in atmosphere to make smog -major health issues , asthma attacks and even death
