What element is used as a shield to protect people from radioactive substances?

The graph below compares the volume occupied by 100 g of liquid water and 100 g of water vapor. (A bar graph is shown with the title, Volume Occupied. The y axis title is, Volume. The x axis title is, Substance. There are two markings on the x axis.

There are mol of hydrogen in 2.8 mol of caffeine

X=124 grams y=49 z=? The product weighs 500 grams what is the mass of z

What is the shorthand orbital notation for Au

When the gases dihydrogen monosulfide and oxygen react, they form the gases sulfur dioxide and water vapor. Write the balanced chemical equation for the reaction.

Is this molecule polar? NaS

The envelope of air that surrounds the earth is called

What is the chemical formula for potassium permanganate?

Is it always possible to identify something as an element compound pure substance or mixture

Why would someone weigh less on Pluto?