A student measured the maximum mass of salt that can dissolve in 100 mL of water at five different temperatures. Which variable should go on the y-axis?

A) the volume of water

B) the temperature of water

C) the mass of water

D) the mass of salt

A.(nh4)(2co3)is the correct answer 

Answer(true);

Radon-222 or rn-222 has a half-life of 3.82 days. to determine the fraction of an original sample of rn-222 that remains unchanged after 7.646 days, we calculate the amount of rn-222 remaining after 7.646 days and divide it with the original amount. using 1 gram as a basis and using half-life calculation methods, we can determine that  0.249 or 0.25  grams of rn-222 will remain, and thus the fraction remaining is 0.25 or 1/4.