The early atmosphere was probably mostly carbon dioxide, with little or no oxygen. <span>The proportion of oxygen went up because of </span>photosynthesis. The photosynthesis was conducted from <span>tiny organisms.
</span><span>cyanobacteria, or blue-green algae. </span><span>
They </span>used sunshine, water and carbon dioxide to produce carbohydrates and, yes, oxygen. This change to the atmosphere was very important because the <span>breathable air we enjoy today was created.</span>
Answer:
[Top row] - Chemical bonds
[2nd Row L-R] - Force, Ionic, Covalent
[3rd Row L-R] - Atoms, Lost or Gained, Shared
[4th Row L-R] - More stable, Metal and Nonmetal, Nonmetal and Nonmetal
Explanation:
<u>Chemical bonds</u> are a<u> </u><u>force</u> that hold together <u>atoms</u> in a substance to make compounds <u>more stable.</u>
<u>Chemical bonds</u> include two kinds: <u>Ionic</u> and <u>Covalent.</u>
<u>Ionic</u> in which electrons are <u>lost or gained</u> where attraction is between a <u>Metal and Nonmetal.</u>
<u>Covalent</u> in which electrons are shared where attraction is between a <u>nonmetal and nonmetal</u>.
I have been able to fill the concept map using the correct terms or phrases. The concept map talks about chemical bonds. There are two types of chemical bonds; which ionic bond and covalent bond.
They discovered that *elements* show increase in atomic numbers across the period.
The answer is A.Hope this helps
Do you mean which one out of water and carbon tetrachloride
if so it will be water