4.) an element cannot be decomposed by a chemical change, it is a pure substance and no other materials compose it.
Answer:
One with a few kinds is more likely to become unstable.
Explanation:
A lack of biodiversity means there is a lower chance of them having traits that enable them to adapt to a changing environment. A lack of biodiversity is usually caused by humans. It could be the result of habitat loss, invasive species, overexploitation, pollution, or climate change.
It is not directly over a flame because it depends on the substance you might not want to heat it too much.you never know what could happen
-<u><em>Oxygen</em></u>
According to Google these are the percentages of the <em>Earths Atmosphere</em>
<em>1</em> 78% - Nitrogen
<u>2</u> 21% - Oxygen
<em>3</em> 0.9% - Argon
<em>4 </em>0.3 - Carbon Dioxide with very small percentage of other elements.