Silicon has three naturally occurring isotopes: Si-28 (mass = 28.0 amu); Si-29 (mass = 29.0 amu), and Si-30 (mass = 30.0 amu). If the average atomic mass of silicon is 29.1 amu, which isotope is the most abundant?

Find the mass of AlCl3 that is produced when 25.0 grams of Al2O3 reacts with excess HCl according to the following reaction. Al2O3 (s) + 6 HCl (aq) –> 2 AlCl3 (aq) + 2 H2O (l)

The volume of a gas with a pressure of 1.2 atm increases from 1.0 L to 4.0 L. What is the final of the gas, assuming no change in the amount of gas or temperature?

How many grams of hydrogen are needed to produce 1.80 g of water according to this equation? 2 H2 (g) + O2 (g) –> 2 H2O (l)

Of the elements: B, C, F, Li, and Ne, the element with the largest atomic radius is

Given the following equation, what is the correct form of the conversion factor needed to convert moles of O2 reacted to the number of moles of Fe2O3 produced? 4 Fe(s) + 3 O2 (g) –> 2 Fe2O3 (s)

What is the coefficient of hydrogen H2 when the following equation is balanced? Al (s) + H2SO4 (aq) –> Al2(SO4)3 (aq) + H2

The force of the collisions of gas molecules against the walls of a container is called

What coefficient placed in front of O2 is needed to complete balancing of the following equation? C5H8 (l) + ? O2 (g) –> 5 CO2(g) + 4 H2O (g)

When solutions of KCl and Pb(NO3)2 are mixed, a precipitate forms. Which of the following is the net ionic equation for the reaction that occurs?