Check in for Living By Chemistry Lessons 18 and 19

How many valance electrons, that is electrons on the outer most ring, does this atom have?

• 2
• 5
• 8
• 15

Answer explanation

Remember the valence electrons are found on the outside ring of the atom. you can only have one valence level and multiple core levels. In this model there were five electrons in total on that outer ring.

Tags

HS-PS1-2

How many valance electrons, that is electrons on the outer most ring, does this atom have?

• 1
• 2
• 3
• 4

Answer explanation

Remember the valence electrons are found on the outside ring of the atom. you can only have one valence level and multiple core levels. In this model there was only one electron in total on that outer ring.

Tags

HS-PS1-2

This atom has (a)   valance electrons, that is electrons on the outer most ring.

• 2
• 8
• 10
• 18

Answer explanation

Remember the valence electrons are found on the outside ring of the atom. you can only have one valence level and multiple core levels. In this model there were eight electrons in total on that outer ring.

Tags

HS-PS1-2

Select all of the valance electrons in this model.

Answer explanation

Remember the valence electrons are found on the outside ring of the atom. you can only have one valence level and multiple core levels. In this model there were four electrons in total on that outer ring.

Tags

HS-PS1-2

What is the net charge on this ion?

Remember that the net charge is found by subtracting the number of electrons fro the number of protons.

Charge = (#protons)-(#electrons)

• -2
• -1
• 0
• +1
• +2

Answer explanation

In this case you had 3 protons and 2 electrons

3-2 = +1 so the charge was +1

Tags

HS-PS1-2

Remember that the net charge is found by subtracting the number of electrons fro the number of protons.

Charge = (#protons)-(#electrons)

This model has 15 protons and 18 electrons in total.

Mathematical Equivalence

ON

Answer explanation

In this case you had 15 protons and 18 electrons .

15-18 = -3 so the charge was -3 charge

Tags

HS-PS1-2

A student says that the atom seen here will form a cation with +5 charge. In 1 or 2 sentences explain why this student is wrong.

Tags

HS-PS1-2

Match the following words to their correct definition

• an ion with a net positive charge.

• Cation

• electron in the inner energy levels

• Valence Electron

• electron on the outer most energy level

• Atomic Number

• number of protons in an atom's nucleus

• Anion

• an ion with a net negative charge.

• Core Electron

Tags

HS-PS1-2

Match the following definitions to the correct vocabulary words

• Shell (Bohr) Model

• A particle that determines how reactive an element is

• Bunsen Burner

• A tool used to heat substances in the lab.

• Electron

• A model of the atom that uses shells (rings) to represent different energy levels of the atom.

• Excited State

• When an electron in an atom is in a higher energy level than normal

• Ground State

• When an electron in an atom is in the lowest energy state it can be.

Tags

HS-PS1-2

Draw an atom that fits the following description

5 protons in the nucleus

6 neutrons in the nucleus

3 electrons in total

Tags

HS-PS1-2