Mass and energy are conserved options:
A) only in physical changes.
B) always in physical changes and sometimes in chemical changes.
C) only in chemical changes.
D) in chemical changes and physical change

i think a, hope it .

explanation:

the correct option is c.

isotopes refers to different forms of the same element with the same atomic number but different mass number as a result of difference in their neutron numbers. isotopes have different relative atomic mass but share the same chemical properties.

what is the average time it took the car to travel 0.25 meters?

⇒ 2.23 seconds

what is the average time it took the car to travel 0.50 meters?

⇒ 3.13 seconds