Carbon dioxide is made up of carbon and oxygen atoms is it an element or a compound

The big bang nucleosynthesis theory states that elements were produced in the first few minutes of the big bang while elements have their origins in the interiors of stars, forming much later in the history of the universe.

Acrystal that absorvd water from air is (blank)a. aqueousb. homogenousc. hygroscopicd. efflorescent

In what environment would mineral formation caused by high pressures and high temperatures most likely occur?