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:

• Analyze the first option: In chemical reactions, new compounds (not isotopes) are formed, and in nuclear reactions, new isotopes (or elements) are formed, so this is incorrect.
• Analyze the second option: Both chemical and nuclear reactions can be represented by balanced equations (nuclear equations balance mass and charge), so this is incorrect.
• Analyze the third option: Chemical reactions involve electron - sharing/bonding changes, leading to small energy changes. Nuclear reactions involve changes in the nucleus (protons/neutrons), releasing large amounts of energy (like in fission/fusion), so this is correct.
• Analyze the fourth option: In chemical reactions, electrons are affected (bonding), and in nuclear reactions, protons/neutrons are affected (nuclear changes), so this is incorrect.

Answer:

The correct statement is: "In chemical reactions, small amounts of energy can be absorbed or released. In nuclear reactions, changes in energy are much larger."