If the half-life of a radioactive substance is 600 years, what fraction of the original material is left after 1,800 years?

Covalent network solids typically have melting points and boiling points. the chemical formula of a network solid indicates in the molecule.

Which of the following words describe the reality that the universe looks the same from various perspective

If many scientists conduct the same or similar experiments, and all obtain similar results, a can be written, which is a generally agreed-upon statement that explains and predicts how a natural phenomenon works.