What is 3 parts of a chemical formula

Iknow #2 is d. i just need to know why

Each of the following reactions is allowed to come to equilibrium and then the volume is changed as indicated. predict the effect (shift right, shift left, or no effect) of the indicated volume change. drag the appropriate items to their respective bins.co(g) + h2o(g) < => co2(g) + h2(g) (volume is decreased) pcl3(g) + cl2(g) < => pcl5(g) (volume is increased) caco3(s)< => cao(s) + co2(g) (volume is increased)

The equation picture below shows which type of nuclear reaction u 235 + n x e 134 + sr 100 + 2n