Which part of the hunman body controls the nervous system

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.

Element before carbon on the periodic table

The diagram below shows the movement of particles. what does this piece of evidence best support? the collision theory the maxwell-boltzmann distribution the effect of pressure on reaction rates the effect of temperature on reaction rates