Arya mixes two chemicals together in a beaker. When she touches the beaker, she notices that it has become very warm.

Question

What type of change most likely happened in the beaker, and why?

Responses

a chemical reaction, because a change in temperature can be evidence that a chemical reaction has taken place
a chemical reaction, because a change in temperature can be evidence that a chemical reaction has taken place

a physical change, because a change of state occurred
a physical change, because a change of state occurred

a chemical reaction, because mixing substances results in chemical changes
a chemical reaction, because mixing substances results in chemical changes

a physical change, because mixing substances does not change the identity of the substances

Answer 1

The correct response is:

a chemical reaction, because a change in temperature can be evidence that a chemical reaction has taken place.

When two chemicals are mixed and the temperature of the beaker increases, it indicates that an exothermic reaction may be occurring. This temperature change is a common sign that a chemical reaction is taking place.