Why is the composition of Earth's atmosphere still changing?
The composition of the atmosphere is changing today as it has been changing since the earth began to cool and atmosphere formed, just as the climate has gone through periods of heating and cooling. There have been multiple "ice ages", and multiple thawings. Ocean levels have gone up and down. Carbon dioxide has been absorbed by plants and buried for centuries, and carbon dioxide levels have gone back up following volcanic eruptions.
Lately, (in the last hundred years) the levels of carbon dioxide has gone up. Scientists believe that pollution from human activity is changing the atmosphere.
- Burning of fossil fuels (coal, oil and natural gas) in industry, transport and the generation of electricity, which releases carbon dioxide (CO2).
- Bad agricultural practices emit methane (CH4), a powerful greenhouse gas.
- Deforestation has removed the trees that used to take carbon dioxide from the atmosphere.
Because soon after the earth formed, when it was still hot and mostly molten, the materials separated themselves out. Most of the denser materials, like nickel and iron, sunk towards the center (being the core) and the lighter materials floated to the surface (the crust). So due to the separation the crust composition is different than the core.
Heating sulfur is a physical change. You're not changing the chemical composition of the sulfur, just the temperature. Now if you heat it to its boiling point and and it changes to a vapor it's a chemical change because you've changed its state of matter.(Actually changing the state of matter of an object is still a physical change, as it does not change the chemical composition of the element)
the moon, it has no atmosphere so all the heat gets in, and then all the heat gets out. that is why it varies from 250F to -250F. The earths atmosphere blocks much of the suns heat but still lets some in, and doesnt let it all leave either. tats why earth is far more moderate than the moon or any other atmosphere lacking object
Well to maintain the oxygen in the earth atmosphere you need to make sure that the level of global warming is decreasing and less fumes will be able to make up the ozone layer. With a thinner layer around the earth this means that oxygen will be able to enter and exit the earths surface, allowing oxygen to still stay in the atmosphere.
Changing state is a physical change. The chemical composition of the substance doesn't change, only the form the substance takes. Liquid water changing to ice is still water-- the chemical composition hasn't changed. An example of chemical change would be methane (CH3) burning in oxygen (O2) to form carbon dioxide (CO2) and water vapor (H2O). The methane and oxygen no longer exist as themselves but have become carbon dioxide and water vapor-- their chemical compositions…