Question 1
An atom of bromine has a mass about four times greater than that of an atom of neon. How many grams of neon will contain the same number of atoms as 1,000 g of bromine?
◦ 4 g Ne
◦ 250 g Ne
◦ 400 g Ne
◦ 1,000 g Ne
◦ 4,000 g Ne
Question 2
An atom of helium has a mass about four times greater than that of an atom of hydrogen. Which choice makes the correct comparison of the relative numbers of helium and hydrogen atoms in equal masses of the two elements?
◦ There are about four times as many helium atoms as hydrogen atoms.
◦ There are about two times as many helium atoms as hydrogen atoms.
◦ The number of helium and hydrogen atoms is the same.
◦ There are about half as many helium atoms as hydrogen atoms.
◦ There are about one-fourth as many helium atoms as hydrogen atoms.
Greater Flamingo
Electrospray mass spectrometry of a protein
The Structure of an Old Low-Mass Star
Body mass index table.
Hydrogen Bonds رابطة هيدروجينية
Relative expression times and amounts of cyclins during the cell cycle