If 7 mol calcium carbide (CaC2) reacts with an excess of water, how many moles of acetylene (C2H2) will be produced? CaC2 + 2 H2O → Ca(OH)2 + C2H2

Answerthe same as;

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.

Answer/when the cell uses energy;