Atoms

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

Fill in the Blanks

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).

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

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​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

​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.

​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

Fill in the Blanks

Fill in the Blanks

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