Valence Electrons & Octets in Diatomic Molecules

According to the image, a hydrogen atom has one valence electron (H·). How many electrons does each hydrogen atom in H2 effectively have access to?

• 1

• 2

• 4

• 8

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NGSS.MS-PS1-1

The image shows Cl2 with the Lewis structure :::Cl:Cl::: How many total valence electrons (dots) are shown around each chlorine atom in this structure?

• 2

• 6

• 7

• 8

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NGSS.MS-PS1-1

An oxygen atom has 6 valence electrons. According to the O2 structure in the image (O::O), how does each oxygen atom obtain access to 8 electrons?

• By gaining 2 electrons from the other atom.

• By sharing 2 of its own electrons and 2 from its partner.

• By losing 2 electrons to the other atom.

• By sharing 4 of its own electrons.

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NGSS.MS-PS1-1

Comparing the Lewis structures, why does chlorine form a single bond (Cl-Cl) while oxygen forms a double bond (O=O)?

• Chlorine atoms are larger.

• Oxygen needs to share more electron pairs to complete its octet.

• Chlorine has more valence electrons to start with.

• Oxygen prefers weaker bonds.

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NGSS.HS-PS1-1

NGSS.HS-PS1-2

Based on the pattern in the image, what is the relationship between an atom's number of valence electrons and the number of bonds it forms in these diatomic molecules?

• Atoms with more valence electrons form fewer bonds.

• Atoms form enough bonds so that shared + unshared electrons = 8 (or 2 for H).

• The number of bonds is always equal to the number of valence electrons.

• There is no clear relationship.

Tags

NGSS.MS-PS1-1

In the N2 molecule, each nitrogen atom has 5 valence electrons. How many electrons from the other nitrogen atom does each nitrogen share to complete its octet?

• 1

• 2

• 3

• 5

The notation H-H shows that in H2, each hydrogen atom contributes __ electron(s) to form the bond.

• 1

• 2

• 4

• 8

Which molecule in the image demonstrates that atoms can complete their octet by sharing multiple pairs of electrons?

• Only H2

• Cl2 and H2

• O2 and N2

• All of them

Looking at :::Cl:Cl::: the bond is formed by one shared pair. The other six dots on each chlorine represent:

• Electrons that will be shared next.

• Protons in the nucleus.

• Lone pairs that belong to that atom only, helping complete its octet.

• Electrons that are transferred.

Tags

NGSS.MS-PS1-1

What fundamental need drives the atoms in the image to form covalent bonds with themselves?

• To become positively charged.

• To increase their atomic mass.

• To achieve a full outer electron shell (octet/duet).

• To release energy as light.

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NGSS.MS-PS1-1