Matter can undergo chemical reactions and nuclear reactions. Which statement is true only for nuclear reactions?
A. The mass of the reactants is conserved.
B. The atoms are reorganized into products,
C. The nuclei of the atoms are reorganized.
D. The energy in the reactants is conserved.

D. is the answer hope that you

The population of unionid mussels decreased after zebra mussels were introduced. zebra mussels competed with the unionid mussels for food. the zebra mussels were able to displace the unionid mussels, allowing the zebra mussel population to increase  over the years. the unionid mussel population decreased because  of lack of food.

Answerchemical;

Answer/when the cell uses energy;