What is the "goal" of an element in bonding chemically (what does it need to do to be stable)

Cucl2 + 2nano3 cu(no3)2 + 2nacl what is the percent yield of nacl if 31.0 g of cucl2 reacts with excess nano3 to produce 21.2 g of nacl? 49.7% 58.4% 63.6% 78.7%

How many miles of water are produced if 5.43 mol pbo2 are consumed

Particle model to predict what will happen if a sharp object creates a hole in the soccer ball