A pure substance is one that a. Has been filtered
b. is an element or compound
c. If found in nature
d. Has been cleaned

What phase of matter has particles that are held together but can flow past each other and takes the shape of a container, filling it from the bottom up?

Which of the following statements is true? a. elements in the last period are radioactive. b. atomic weight is the same as atomic mass. c. elements in the same group have the same number of electron shells. d. atomic number equals the number of neutrons in the nucleus of an atom.

Which step in naming unsaturated hydrocarbons is used for alkenes but not alkynes