Which clue can be used to identify a chemical reaction as a replacement reaction? the reaction has two reactants with ions that seem to switch places. the reaction has a single reactant that changes into two or more products. the reaction involves oxygen reacting with a hydrocarbon and giving off heat. the reaction involves a single product forming from two or more reactants.

Option (a) is the correct answer.

Explanation:

When only one element gets displaced upon chemical reaction between a compound and an element then it is known as a single replacement reaction.

For example,

On the other hand, when two compounds chemically react together and their ions get replaced by each other then it is known as a double replacement reaction.

For example,  

Thus, we can conclude that the reaction which has two reactants with ions that seem to switch places clue can be used to identify a chemical reaction as a replacement reaction.

a high pressure system is a dense air mass that is usually cooler and drier than the surrounding air. a low pressure system is a less dense air mass that is usually wetter and warmer than the surrounding air.

in general, areas that experience high atmospheric pressure also experience fair weather. low pressure systems can cause the formation of clouds and storms. air usually flows from areas of high pressure to areas of low pressure..