Relative atomic and molecular masses, the Avogardo constant and the mole

Question 1

What is the relative atomic mass (Ar)?

Answer 1

the weighted average mass of an atom of an atom, taking into account its naturally occuring isotopes

it is relative to 1/12 of the relative atomic mass of an atom of carbon 12

average mass of one atom / 1/12 mass of one atom of carbon-12

Question 2

What is the difference between relative formula mass and relative molecular mass?

Answer 2

relative formula mass is used for ionic compounds because they don’t exist as molecules

both have the symbol Mr

Question 3

How are atoms counted?

Answer 3

weigh large numbers of them because it is impossible to weigh them individually

Question 4

How many atoms are in 1g of hydrogen?

Answer 4

6.022 x 10^23

Question 5

What is the Avogrdo constant?

Answer 5

the number of atoms in 12g of carbon-12

Question 6

What is a mole?

Answer 6

1 mole is equal to an amount of a substance that contains 6.022 x 10^23 particles

Question 7

What is the equation for the number of moles?

Answer 7

mass, m (g) / mass of 1 mole M (g)

Question 8

State why the precise relative atomic mass quoted in the table for the 12C
isotope is exactly 12.00000

Answer 8

by definition

standard / reference value