Atomic Mass and Weight

Question 1

Define Atomic Mass Units

Answer 1

A unit of mass equal to 1/12 the mass of a Carbon 12 atom Approximately (1.660540 x 10^-27 Kg)

Question 2

What is a Proton’s mass in amu’s

Answer 2

A proton has approximately 1.007 atomic mass units

Question 3

What is a Neutron’s mass in amu’s

Answer 3

A Neutron has approximately 1.008 Atomic Mass Units

Question 4

What is a Proton’s mass in grams

Answer 4

A Proton has a mass of 1.6726219 x 10^-24 grams

Question 5

What is a Neutron’s mass in Grams

Answer 5

A Neutron has a mass of 1.674920 x 10^-24 grams

Question 6

Explain Average Atomic Mass

Answer 6

Because there exists different Isotopes of elements. The Average Atomic Mass is calculated by averaging the mass of these Isotopes found in Nature.

Question 7

How do you calculate the Atomic Weight

Answer 7

You list every Isotope of an element with the percentage that its found in Nature.

Then you multiply that out by its corresponding Atomic Mass Unit of each listed Isotope.

Finally, you add each answer together. This is the Atomic Weight Found at the bottom of Each Element in the Periodic Table.

Question 8

How many atoms are in 12 grams of Carbon-12

Answer 8

There are 6.02214076 x 10^23 atoms in 12 grams of Carbon-12

Question 9

Define Avogadro’s Number

Answer 9

6.02214076 x 10²³

(The number of atoms or molecules in one mole of a substance)

Question 10

Define Mole

Answer 10

A Mole is the unit of measurement for amount of Substances in the International System of Units.

It is equal to 6.02214076 x 10²³

Question 11

Explain how to convert Amu to Grams

Answer 11

An Atomic Mass Unit is approximately Approximately (1.660540 x 10^-24 g)

You multiply the AMU’s in grams by the atoms atomic weight

Then multiply by Avogadro’s number (6.02214076 x 10²³)

Question 12

What do you get in a mole of an Element?

Answer 12

Because you are using Avogadro’s number, a Mole of en element will be that elements atomic wieght in grams.

(A mole of Carbon will approximately be 12 grams of Carbon because Carbon’s atomic mass is 12.011)

Question 13

How do you calculate the number of moles in an element

Answer 13

First you convert the units of amount of substance you have into grams

Then you use dimensional analysis to multiply that number by the Number of Moles/ amount of atomic masss.

If you want to calculate the number of atoms, you can use dimensional analysis for 1 mole/ 6.02214076 x 10²³ atoms.