How big would an atom have to be to have the nucleus be as big as a marble?

A balloon contains a mole of helium.  What mass of helium does the mole contain?

In the following unbalanced chemical equation, what coefficient should be placed in front of H2O, when balanced? PCl3 +  H2O

Lithium could form an ionic compound with ________.

How many valence electrons are in an ion of lithium (Li+)?

Alcohols are good fuels, undergoing combustion to produce energy. Below is an unbalanced equation for the combustion of methanol. What coefficients should be placed in the blanks from left to right when balanced? CH3OH + O2

What is the molar mass of chlorine gas (Cl2)?

If magnesium created an ionic compound with chlorine, the chemical formula would be MgCl2.

Which of the following is the BEST definition of heat?

If two atoms of phosphorus bonded together to make a stable molecule, what kind of bond would exist between them?