Which of the following gases is not found in earth’s atmosphere? a. oxygen c. hydrogen b. nitrogen d. all of the above are in the atmosphere

1 a

2 d

3 a

4 c

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