I need to know the measurements of this to the appropriate amount of significant figures

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.

According to the tide table below what time of day will the highest tide occur?

If 1.8 l of water is added to 2.5l of a 7.0 m koh solution, what is the molarity of the new solution