Not to be too picky, but the question ought to say a positively charge ion rather than atom.
I will assume that is what you mean. An ion, using ordinary means, will be positive if it loses electrons (which are negative).
An ion can never gain protons. Left alone, the nucleus will remain unchanged for the rest of eternity. D is wrong.
C is wrong. If electrons are gained, the ion will go negative.
B is wrong for the same reason D is. An ion can't gain protons and it can't lose them.
A is the answer.
<u>Answer:</u>
<em>It is the biosphere and hydrosphere that interact when a drought causes a wildfire that destroys a forest.
</em>
<u>Explanation:</u>
Hydrosphere consists of all the water bodies of earth like oceans, seas, rivers, lakes etc. a drought occurs due to scarcity of water which affects the hydrosphere. The scarcity of water causes plants and trees to dry up and become more prone to catching fire
Biosphere includes all the living organisms of the earth. It includes plants, trees, birds, insects, animals etc. A drought dries up a whole area and a small fire that starts up somewhere in a forest would then engulf the whole forest.
Structures in plant leaves that open and close to maintain homeostasis are called stomata. This is where gases would diffuse in and out of the leaf.
The blood cells likely placed in a "hypotonic solution".
<u>Option: A</u>
<u>Explanation:</u>
When human blood cells are immersed in a solution with a low concentration of solute than is present in cells, osmosis allows water to pass through the cells, allowing the cells to get swollen; such a fluid is hypotonic to the cells. But when held in a solution with a greater concentration of solute, osmosis allows water to pass out of the cell, the cell is smaller and crenated in form; then a solution is hypertonic to the cells.
Healthcare facilities preserve human blood cells in a plasma solution that has the proper salt and protein ratios. Such solution is formulated to be mildly hypertonic to the red cells, thus maintaining the integrity of the cells and avoiding hemolysis.
If the chemical touches another chemical, then there is a higher probability that it's going to react.