Density= mass/volume
= 100/25
density = 4g/ml
The formula is for 1 Calcium, 3 Magnesium, 4 Carbon, & 12 Oxygen. The 4 after the parenthesis of (CO3) distributes to each element.
Answer : There are 4 Carbon atoms in the formula.
Mesosaurus lived in freshwater lakes and ponds. Elongated and slim, it measured about 3.3 feet long. The skull and tail were both long and narrow, and the animal probably undulated through the water as it fed on small crustaceans and other prey with its jaws, which were full of long, thin, pointed teeth.
The characteristic of the Bohr model that would best support his observation is this assumption: "The energy of the electron in an orbit is proportional to its distance from the nucleus. The further the electron is from the nucleus, the more energy it has." The discrete, bright, colored lines might represent the electrons and its distance from the nucleus. The lights are caused by the energy it has.
The answer is c hopefully I helped you