A mixture of gases contains 0.300 moles of argon gas and 0.700 moles of helium gas. The mixture is at constant temperature and has a total pressure of 0.350 atm. What is the partial pressure of each gas

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