Step 4: Measure the Mass of the Book

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 of the following is always a reactant in a combustion reaction? oxygen nitrogen hydrogen carbon

The minerals found in bones are deposited by living cells called