What’s the percent of chlorine in CaCl2

the answer is   c.) 1575 j.

explanation:

because u need two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei to form isotopes.

so since they all have the same shape? i mean maybe because m& m and reeses are both chocolates

i would say b

explanation:

but i think i would need more information than that