Atoms and Molecules review

Which of the following is not considered a molecule?

• Au

• O₂

• CO₂

• H₂O

Answer explanation

Au is an atom/element.

The definition of molecule is 2 or more atom stuck together. Au is just one atoms of gold.

Tags

NGSS.MS-PS1-1

Which of the following describes at atom?

• Is made of protons, neutrons and electrons

• Is the smallest piece of matter

• Stick together to make molecules

• Are like words.

Tags

NGSS.MS-PS1-1

Electrons are...

• Found inside the atom and have a negative charge.

• Are found outside the atoms and have a positive charge

• Are found inside the atom and have a positive charge

• Are found outside the atoms and have a negative charge

Answer explanation

Electrons move around the atom and have a negative charge

Tags

NGSS.MS-PS2-3

How many protons are in Chromium?

• 24

• 52

• 28

• 76

Answer explanation

The answer is 24. There are also 24 electrons to make the atoms neutral.

52 represents the mass of the atom.

How many neutrons are in Chromium?

• 24

• 52

• 28

• 76

Answer explanation

The answer is 28.

52-24=28 neutrons in the center

Tags

NGSS.MS-PS1-1

How many electrons can fit on the innermost circle?

• 2

• 8

• 7

Answer explanation

The innermost circle can hold up to 2 electrons. The next circle can hold up to 8.

What types of atoms are found in Al₂O₃

• Aluminum

• Oxygen

• Iodine

• Carbon Dioxide

Tags

NGSS.MS-PS1-1

How many Aluminum atoms are in Al₂O₃

• 1

• 2

• 3

• 5

Answer explanation

Al = Aluminum

O = Oxygen

Al₂O₃

There is a 2 next to the Al meaning that there are 2 aluminum atoms (Al₂)

Tags

NGSS.MS-PS1-1

How many Oxygen atoms are in Al₂O₃

• 1

• 2

• 3

• 5

Answer explanation

Al = Aluminum

O = Oxygen

Al₂O₃

There is a 3 next to the O meaning that there are 3 oxygen atoms (O₃)

Tags

NGSS.MS-PS1-1

How many Oxygen atoms are in 2Al₂O₃

• 7

• 2

• 6

• 10

Answer explanation

Tags

NGSS.MS-PS1-1