What do the dots in a Lewis dot structure represent?

• Molecules.

• Protons.

• Valence electrons.

• Atoms.

Answer explanation

Valence electrons are the electrons in the valence shell of an atom. The valence shell of an atom is made up of the atomic orbitals in the highest principal energy level of the atom.

When we draw the Lewis dot structure for an atom, we first write down the element symbol for the atom. Then, we draw dots around the element symbol. The number of dots we draw is equal to the number of valence electrons in the atom.

What is the Lewis dot structure for a neutral atom of bromine (₃₅Br)?

• The element symbol Br with 7 dots around it.

• The element symbol Br with 8 dots around it.

• The element symbol Br with 5 dots around it.

• The element symbol Br with 35 dots around it.

Answer explanation

The Lewis dot structure for a neutral atom of bromine (₃₅Br) should be made up of the element symbol Br with 7 dots around it. These 7 dots represent the 7 valence electrons in a neutral atom of bromine.

Tags

NGSS.HS-PS1-1

What is the Lewis dot structure for a neutral atom of sodium (₁₁Na)?

• The element symbol Na with 11 dots around it.

• The element symbol Na with 8 dots around it.

• The element symbol Na with 1 dot around it.

• The symbol Na with 2 dots around it.

Answer explanation

The Lewis dot structure for a neutral atom of sodium (₁₁Na) should be made up of the element symbol Na with 1 dot around it. This 1 dot represents the 1 valence electron in a neutral atom of sodium.

What is the Lewis dot structure for a neutral atom of carbon (₆C)?

• The element symbol C with 5 dots around it.

• The element symbol C with 4 dots around it.

• The element symbol C with 2 dots around it.

• The element symbol C with 8 dots around it.

Answer explanation

The Lewis dot structure for a neutral atom of carbon (₆C) should be made up of the element symbol C with 4 dots around it. These 4 dots represent the 4 valence electrons in a neutral atom of carbon.

Tags

NGSS.HS-PS1-1

What is the Lewis dot structure for a neutral atom of iron (₂₆Fe)?

• The element symbol Fe with 2 dots around it.

• The element symbol Fe with 8 dots around it.

• The element symbol Fe with 52 dots around it.

• The element symbol Fe with 26 dots around it.

Answer explanation

The Lewis dot structure for a neutral atom of iron (₂₆Fe) should be made up of the element symbol Fe with 2 dots around it. These 2 dots represent the 2 valence electrons in a neutral atom of iron.

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

What is the Lewis dot structure for a neutral atom of phosphorus (₁₅P)?

• The element symbol P with 15 dots around it.

• The element symbol P with 8 dots around it.

• The element symbol P with 3 dots around it.

• The element symbol P with 5 dots around it.

Answer explanation

The Lewis dot structure for a neutral atom of phosphorus (₁₅P) should be made up of the element symbol P with 5 dots around it. These 5 dots represent the 5 valence electrons in a neutral atom of phosphorus.

Tags

NGSS.HS-PS1-1

What is the Lewis dot structure for a neutral atom of xenon (₅₄Xe)?

• The element symbol Xe with 8 dots around it.

• The element symbol Xe with 6 dots around it.

• The element symbol Xe with 2 dots around it.

• The element symbol Xe with 54 dots around it.

Answer explanation

The Lewis dot structure for a neutral atom of xenon (₅₄Xe) should be made up of the element symbol Xe with 8 dots around it. These 8 dots represent the 8 valence electrons in a neutral atom of xenon.

NOTE!

A Lewis dot structure will only ever have 8 dots around it because an atom will only ever have, at most, 8 valence electrons. This is the case for our purposes in this class.

Tags

NGSS.HS-PS1-1

What is the Lewis dot structure for a neutral atom of boron (₅B)?

• The element symbol B with 2 dots around it.

• The element symbol B with 8 dots around it.

• The element symbol B with 5 dots around it.

• The element symbol B with 3 dots around it.

Answer explanation

The Lewis dot structure for a neutral atom of boron (₅B) should be made up of the element symbol B with 3 dots around it. These 3 dots represent the 3 valence electrons in a neutral atom of boron.

What is the Lewis dot structure for a neutral atom of uranium (₉₂U)?

• The element symbol U with 92 dots around it.

• The element symbol U with 2 dots around it.

• The element symbol U with 8 dots around it.

• The element symbol U with 6 dots around it.

Answer explanation

The Lewis dot structure for a neutral atom of uranium (₉₂U) should be made up of the element symbol U with 2 dots around it. These 2 dots represent the 2 valence electrons in a neutral atom of uranium.

Tags

NGSS.HS-PS1-1

What is the Lewis dot structure for a neutral atom of lead (₈₂Pb)?

• The element symbol Pb with 8 dots around it.

• The element symbol Pb with 4 dots around it.

• The element symbol Pb with 82 dots around it.

• The element symbol Pb with 28 dots around it.

Answer explanation

The Lewis dot structure for a neutral atom of lead (₈₂Pb) should be made up of the element symbol Pb with 4 dots around it. These 4 dots represent the 4 valence electrons in a neutral atom of lead.