You are asked to design an experiment to measure the enthalpy of a given reaction. The reaction needs to be at atmospheric pressure so which of the following techniques would be ideal for this experiment?

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 the energy in joules of a mole of photons associated with visible light of wavelength 486 nm?

Match each statement with the state of matter it describes