Positive ions from a base and negative ions from an acid form .

Explanation:

Bases are the species which contain ions whereas acids are the species which contain ions. When positive ions from a base reacts with negative ions of an acid then it results in the formation of salt.

For example, when base NaOH reacts with hydrochloric acid then it results in the formation of sodium chloride and water.

The reaction is as follows.

Thus, we can conclude that positive ions from a base and negative ions from an acid form a salt.

organisms are more likely to be more preserved in mud than sand because mud is moist and wet, while sand is very dry.