If your density was supposed to be 2.3 g/mL, but you calculated yours to be 2.1 g/mL, what is your percent error?

If the atomic mass of an atom is 34 and the atom contains 13 protons, how many neutrons does the atom contain?

Zoe is investigating the composition of substance a, an unknown substance. using chemical processes, she analyzes substance a and determines it is composed of sodium, oxygen, and hydrogen atoms in a ratio of 1 : 1 : 1. what is substance a? a. a compound b. an element c. a heterogeneous mixture d. a homogeneous mixture

How many moles of al3+ ions are in 1.25 moles of al2o3