Answer:
The answer is A. Polar covalent; negatively
Explanation:
Hydrogen bonds form between molecules containing polar covalent bond the hydrogen bond is been a hydrogen atom of one molecule and a partially negative charged atom of another.
Example 
(water):- It contain a slight positive charge on one side and a slight negative charge on the other.
When humans burn fuel/cut down tress, they will increase the level of carbon dioxide within the atmosphere. Tress "inhale" the carbon dioxide within the atmosphere and without them, the excess will still linger. Carbon dioxide is a byproduct of burning fuel thus, it will increase the levels in the atmosphere.
I’m not really sure what the qn is asking for but if i’m not wrong it should be ‘1’ for each blank!
The answer is powder because if it was a small crystal it the molecules are tightly compact same with the small cube but there less compact, powder is loose and more spread out and easier to mix so it would react the fastest
