Answer:
There are way in separating mixtures of chloride salts such as that of sodium chloride and ammonium chloride. It can be done by crystallization, filtration, and sublimation. The easiest method among the three is separation by sublimation.
The early precambrian atmosphere consisted primarily of nitrogen and carbon dioxide with almost no oxygen.
<span>Today, the atmosphere contains about 20% oxygen, less carbon dioxide and similar amounts of nitrogen. </span>
<span>Photosynthetic green-leaf plants and trees are largely responsible for the change, converting carbon dioxide to oxygen.</span>
Conservation efforts most effective if <span>Conservation efforts are most effective when multiple groups cooperate. The answer is letter A. The rest of the choices do not answer the question above</span>
