Why does the atoms have to be the same numbers

Coquina, a type of limestone, forms from shell fragments that settle on the ocean floor. what type of rock is coquina?

Based on the law of dominance, we would expect percent of the offspring from this cross to have large teeth.

Nephrons, the functional unit of kidneys, are responsible for formation of urine. the sentences describe situations that are the result of problems in the urine formation process. for the nephron shown below, match each situation to the step in the urine formation process where the problem lies.