When determining whether a chemical reaction has taken place you observe and look for several indicators. Which would be considered an indication that a chemical reaction or chemical change has taken place? es -) A) Solid melts. B) Heat is given off. Substance dissolves D) Substance changes shape. Physical Science

B) Heat is given off.

Explanation:

When heat is given off, a chemical change must have occurred and such a reaction is termed an exothermic reaction.

A chemical change is one in which;

Most chemical reactions are accompanied by heat changes.

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in 1783 cavendish was working with his hydrogen gas and found that when he burned it and condensed the vapor it was water. this was very significant since it disproved the greek theory of elements completely since water was not a simple substance but the product of two gases. it was lavoisier who hearing of the experiment gave cavendish's gas the name hydrogen ("water-producer") and added that hydrogen burned by combining with oxygen and that water was a hydrogen-oxygen combination.

explanation: