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>
U won’t get hyperthermia or a heat stroke when ur hot u use up more energy but when ur cold u use up less
1 is B (Just remember to have the same number of atoms on both sides)
2 is B (A precipitate is a solid forming from 2 liquids)
Water has hydrogen bonds between Hydrogen atoms (that are slightly positive in molecules of water ) and Oxygen atoms (that are slightly negative in molecules of water), so it is necessary more energy to break them down and move water molecules from liquid state to gas.