Which of the following is true of reproduction? ​

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.

You have 125g of a certain seasoning and are told that it contains 76.0 g of salt what is the percentage of salt by mass in this seasoning

4786 joules of heat are transferred to a 89.0 gramsample of an unknown material, with an initialtemperature of 23.0°c. what is the specific heat of thematerialif the final temperature is 89.5 °c?