Question

which statement correctly compares chemical reactions with nuclear reactions?
in chemical reactions, new isotopes are formed. in nuclear reactions, new compounds are formed.
chemical reactions can be represented by balanced equations. nuclear reactions cannot be represented by balanced equations.
in chemical reactions, small amounts of energy can be absorbed or released. in nuclear reactions, changes in energy are much larger.
in chemical reactions, only protons and neutrons are affected. in nuclear reactions, only electrons are affected.

Explanation:

1. In chemical reactions, electrons are involved in bonding and no new isotopes are formed. In nuclear reactions, new isotopes or elements can be formed, not new compounds in the traditional sense. So the first option is incorrect.
2. Both chemical and nuclear reactions can be represented by balanced equations. Chemical reactions balance atoms and nuclear reactions balance mass - number and atomic number. So the second option is incorrect.
3. Chemical reactions involve relatively small energy changes related to electron - bonding changes. Nuclear reactions involve much larger energy changes due to changes in the nucleus. This is correct.
4. In chemical reactions, electrons are involved in bonding and reactivity. In nuclear reactions, protons, neutrons, and other sub - atomic particles in the nucleus are affected. So the fourth option is incorrect.

Answer:

In chemical reactions, small amounts of energy can be absorbed or released. In nuclear reactions, changes in energy are much larger.