Which two particles have approximately the same mass?
(1) proton and neutron
(2) proton and electron
(3) neutron and electron
(4) neutron and positron

According to periodic trend, which of the following most likely has the highest ionization energy? kr be ni sc

What is the molar mass of the anhydrous compound? answer using four significant figures. 36.02 g/mol 120.15 g/mol 156.12 g/mol

What would be the original temperature of a gas that has a volume of 2.0 l and a pressure of 2.0 atm and an unknown temperature that the volume increased to 3.5 l in its pressure decreased to 1.0 atm if the final temperature is measured to be 11°c