Which of the following is true regarding the atoms involved in a chemical reaction? 1.Some of the atoms will always be changed into a different type of atom by a chemical reaction.

2.Some of the atoms present before the reaction will always be lost during a chemical reaction.

3.During a chemical reaction, atoms will always be combined into much larger molecules.

4.The same number of each type of atom will always be present before and after a chemical reaction takes place.