PLSS HELP ITS RLLY HARD awnser deez 2 questions pls

Omg imgonnafailnfiedkla use complete sentences to explain how the mass of hydrogen is conserved during cellular respiration.

1) this is the structure in the cell nucleus that houses a cell's genetic information

Water undergoes a large change in density at 0 ∘ c as it freezes to form ice. calculate the percent change in density that occurs when liquid water freezes to ice at 0 ∘ c given that