Consider the substance. 1 mol of beryllium 1 mol of salt 1 mol of water 1 mol of hydrogen Which statement is true about these substances?

One mole of each substance contains the same number of particles: Avogadro’s number, so B is not true. But the particles have different molar masses—for example, 1 mol of hydrogen gas has a mass of about 2 g, while 1 mol of water has a mass of about 18 g. Therefore, the substances have different masses, making A correct.

AI-written and checked against the verified answer.