Atoms

​Let's Review Atoms and Learn About Atomic Mass!

Fill in the Blanks

Atoms are known as the

blocks of matter.

Multiple Choice

The smallest particle of any type of matter is a (an) ___

• element

• compound

• chemical

• atom

Multiple Choice

1.                      Which distinguishes an atom of one element from an atom of a different element?

 

• the number of neutrons and protons

• the number of neutrons

• the number of electrons

•   the number of protons

Multiple Choice

Which of the following subatomic particles can be found inside the nucleus of an atom

• electrons only

• neutrons only

• protons and neutrons

• electrons and protons

Multiple Choice

   Which accounts for most of the mass of an atom?

 

• neutrons and protons

• protons

• electrons and neutrons

• electrons

Multiple Choice

  Which describes an atom with an atomic number of 9?

 

• 10 protons, 9 neutrons

• 9 protons, 10 neutrons

• 4 protons, 5 neutrons

• 3 protons, 3 neutrons

​Let's Learn Something New!

​WHAT IS THE ATOMIC MASS OF AN ATOM?

​Each ELEMENT has an ATOMIC WEIGHT that is equal to the number of protons plus the number of neutrons (in one atom of the element).

​

​Oxygen has an atomic number of 8 and atomic mass of 15.999. We can determine the number of NEUTRONS in an oxygen atom.

​

​That's right! We can find the # of neutrons in an oxygen atom because we already know the number of protons.

​

Fill in the Blanks

How many protons are in an oxygen atom?

​The number of protons in an atom is equal to the atomic number of the atom.

An atom of oxygen has 8 protons.

​To find the number of neutrons in an oxygen atom:

1. Round the atomic mass to the nearest whole number.                  2. Subtract the atomic number from the rounded atomic mass.

​1. 15.999 rounds to 16.

2. Atomic mass - atomic number = # of neutrons.

​

Answer: 16-8= 8 neutrons

​Find the number of neutrons in an atom of boron.

1. Round the atomic mass to the nearest whole number.

Fill in the Blanks

What is 10.811 rounded to the nearest whole number?

​2.  Subtract the atomic number from 11.

What is your answer?

​

6 is the number of neutrons in a boron atom.

Great job!​

​How many neutrons are in an atom of lithium?

​

​1. Round the atomic mass to the nearest whole number.

​2. Subtract the atomic number from the atomic mass.

Fill in the Blanks

How many neutrons are in a lithium atom?

Fill in the Blanks

How many neutrons are in a silicon atom?

Fill in the Blanks

How many neutrons are in an atom of sodium?

Multiple Choice

What is the atomic number of this element?

• 70

• 79

• 80

• 200

Multiple Choice

What is the chemical (or element) symbol of gold?

• Ag

• Gold

• Au

• AGT

Multiple Choice

How many neutrons are in an atom of gold?

• 118

• 197

• 128

• 79