Which scientist established the law of octaves?

What is the specific heat of a substance that absorbs 2.5×10^3 joules of heat when a sample of 1.0 ×10^4g of the substance increases in temperature from 10°c to 70°c?

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.

What is an example of a physical property?