Each helium atom has two protons. Sketch models of helium-3 and helium-4 which have approximate masses of 3 amu and 4 amu, respectively. Label and differentiate protons, neutrons, and electrons in your models.

What is the chemical formula of the following compound

If a solution is considered basic, then a) the hydroxide ion and hydronium ion concentrations are equal. b) the hydroxide ion concentration is less than the hydronium ion concentration. c) the hydronium ion concentration is greater than the hydroxide ion concentration. d) the hydroxide ion concentration is greater than the hydronium ion concentration.

What are the similarities of physical and chemical change ?