1)what distinguishes an atom of one element from atoms of all other elements?
2)some scientists have hypothesized that meterorites have periodically bombarded the earth, causing mass extictions every 26 million years. how might this hypthesis be tested?
3)according to the big bang theory, the original big bang took place about 15 billion years ago. how might scientists have been able to determine this?
4)calcium chloride is an ionic compound. carbon dioxide is a covalent compound. which of these compounds would you expect to have a lower melting point? explain.
5)is diatomic molecule more likely to be held together be a covalent bond or an ionic bond? explain why you think so.
6)what happens to the chemical properties of a substance when it becomes part of a mixture?
2)some scientists have hypothesized that meterorites have periodically bombarded the earth, causing mass extictions every 26 million years. how might this hypthesis be tested?
3)according to the big bang theory, the original big bang took place about 15 billion years ago. how might scientists have been able to determine this?
4)calcium chloride is an ionic compound. carbon dioxide is a covalent compound. which of these compounds would you expect to have a lower melting point? explain.
5)is diatomic molecule more likely to be held together be a covalent bond or an ionic bond? explain why you think so.
6)what happens to the chemical properties of a substance when it becomes part of a mixture?