Which of these is WRONG?

• A

• B

• C

• D

Answer explanation

D is wrong because the final electron must have the same spin as the other electrons in its orbital. The others are up, so that electron must be up as well.

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

The correct lewis dot diagram for nitrogen would be

• E

• F

• G

• H

Answer explanation

Nitrogen has 5 valence electrons, so the correct lewis dot diagram has 5 dots

Tags

NGSS.HS-PS1-1

Which of these could be the lewis dot diagram for an oxygen anion?

• A

• B

• C

• D

Answer explanation

Oxygen has 6 valence electrons, but it wants 8. Therefore, it will steal 2 electrons so that it has a total of 8 electrons. Choice A has 8 electrons.

Tags

NGSS.HS-PS1-1

Which is the correct lewis dot diagram for carbon?

• D

• E

• F

• G

• H

Answer explanation

Carbon has 4 valence electrons, so the lewis dot diagram should have only 4 dots.

Tags

NGSS.MS-PS1-1

Which of these is the correct Bohr model for fluorine?

• 
• 
• 
• 

Answer explanation

Fluorine is in the 2nd period, so it has 2 electron shells. It's a halogen, so it has 7 valence electrons. The only one that has that many valence electrons is B. You can also count the total number of electrons, which is 9. That's how many electrons a neutral atom of fluorine has.

Tags

NGSS.HS-PS1-1

Put these in the correct order

• 3p

• 1s

• 2s

• 2p

• 3s

Tags

NGSS.HS-PS1-1

Which of the following shows the correct electron configuration for oxygen?

• 1s2 2s2 2p4

• 1s2 2s2 2p6

• 1s2 2s2 2p8

• 1s2 2s2 2p2 3s2

Tags

NGSS.HS-PS1-1

Match the following models of the atom with what was wrong with each.

• Thought atoms had different shapes that gave substances their properties

• 
• Didn't know about orbitals and suborbitals

• 
• Doesn't include any subatomic particles

• 
• Didn't know electrons orbited in specific energy levels

• 
• Didn't know about the nucleus

• 

Tags

NGSS.HS-PS1-8

An atom with 2 protons and 2 electrons would have a charge of ​ (a)   . An atom with 15 protons and 18 electrons would have a charge of ​ (b)   . An atom with 12 protons and 10 electrons would have a charge of ​ (c)   . An atom with 5 protons and 2 electrons would have a charge of ​ (d)   . An atom with 7 protons and 10 electrons would have a charge of ​ (e)  

• 0
• -3
• +2
• +3

Tags

NGSS.HS-PS1-1

An atom has the configuration 1s2 2s2 2p3. Which element is this?

• lithium

• boron

• nitrogen

• oxygen

Answer explanation

Add up all of the electrons - it has 7 electrons, so it must be nitrogen.

Tags

NGSS.HS-PS1-1