Which statement best explains why mercury is considered an element?
a. it is a metal that is a poor conductor of heat.
b. it is a metal that is naturally a liquid at room temperature.
c. it is a poison that is easily absorbed through unbroken skin.
d. it is a substance that cannot be chemically broken down any further. user: niels bohr had a theory about the structure of an atom. which part of his theory has been proven wrong?
a. an atom is mostly empty space.
b. atoms are