Question

4. Which of the following statements are True for chemical reactions? a. The number and types of atoms are the same in the products and the reactants. b. Different isotopes of the same element behave similarly. c. Only the valence electrons are involved. d. New elements are often formed.

Answer 1

a) always true since matter cant be made/destroyed
b) not true since isotopes have diff no of neutrons so chemical structure is different therefore reactivity is different
c) not true since other atoms in inner rings can react too but valence leave/attach to atom first
d) new elements are not formed. new products (compounds) are formed

so the answer is A

Answer 2

THANKS!!!