a bar of gold is melted into liquid the liquid is then poured into a mold to make pieces of jewelry is the process a chemical change or a physical change?

Q: what are the mass number and charge of an electron, respectively?

Why are ionic bonds stronger than covalent bonds?

Carbon dioxide, or CO2, is a (n) A.) atom. B.) mixture. C.) element. D.) compound.

Which equation is a decompostion reaction?

If you had 0.681 moles of caso4.2h2o, how many moles of h2o would you have?

Which of the following is a chemical property? A.) Ability to burn B.) Mass C.) Density D.) All of the above

What is the density of rock if it has a mass of 25 g?

In a popular classroom demonstration, solid sodium is added to liquid water and reacts to produce hydrogen gas and aqueous sodium hydroxide. part a write a balanced chemical equation for this reaction.

Calculate the vapor pressure lowering on an aqueous solution of glycerin that contains 180g of glycerin and 1000g of water at 25c. The vapor pressure of water at this temperature is 23.8torr.

Why does one Oxygen atom bond with two Hydrogen atoms to form water? Why don't they bond in a different ratio?