Answer:
Widening of blood vessels.
Explanation:
The reduction of aldehydes, ketones, organic acids causes the formation of alcohols that is used for different process in the human body. This alcohol increase the width of the blood vessels as it enters the bloodstream causing greater flow of blood to the skin surface as well as temporary feeling of warmth. It also increased heat loss and rapid body temperature decrease that produces cooling effect in the body.
The activity series goes top to bottom, most active to least active elements, going: Li, K, Ba, Sr, Ca, Na, Mg, Mn, Zn, Fe, Cd, Co, Ni, Sn, Pb, H, Cu, Ag, Hg, Au.
Thus, your list of metals would go from most reactive to least reactive: Li, K, Mg, Zn, Fe, Cu, Au
Answer:C
Explanation: they break apart into ions as they dissolve into solution this process is known as dissociation.
When a single compound breaks down into two or more compounds or elements in a chemical reaction then it is known as decomposition reaction.
The chemical symbol for sodium carbonate is
.
The decomposition of sodium carbonate is:

The decomposition of sodium bicarbonate,
will result in the formation of sodium oxide,
and carbon dioxide,
.
Hence, carbon dioxide,
will produce with sodium oxide,
on decomposition of
.