Worksheet: Lewis Structures

In this worksheet, we will practice drawing Lewis structures of compounds from their names or formulas and counting the numbers of lone and valence electrons.

Q1:

Which of the following is the correct Lewis structure for OH?

  • A
    OH
  • B
    OH
  • C
    OH
  • D
    OH
  • E
    OH

Q2:

Which of the following is the correct Lewis structure for I3?

  • A
    III
  • B
    III
  • C
    III
  • D
    III
  • E
    III

Q3:

Which of the following is the correct Lewis structure for B(OH)3?

  • A
    BOOOHHH
  • B
    BOOOHHH
  • C
    BOOHHHO
  • D
    BHHHOOO
  • E
    BOOOHHH

Q4:

Which one of the following is the correct Lewis structure of PH3?

  • A
    PHHH
  • B
    PHHH
  • C
    P+HHH
  • D
    PHHH
  • E
    PHHH

Q5:

Which of the following is the correct Lewis structure for HCl?

  • A
    HCl
  • B
    HCl
  • C
    HCl
  • D
    HCl
  • E
    HCl

Q6:

Which of the following is the correct Lewis structure for SO3?

  • A
    SOOO
  • B
    SOOO
  • C
    SOOO
  • D
    SOOO
  • E
    SOOO

Q7:

Nitrous oxide (NO)2, commonly known as laughing gas, is used as an anesthetic in minor surgeries, such as the routine extraction of wisdom teeth. Including lone pairs, give the structural formula of nitrous oxide.

  • A
    ONN
  • B
    NNO

Q8:

Which of the following is not a step taken when drawing out a Lewis structure?

  • APlace the leftover electrons on the central atom.
  • BCount the valence electrons.
  • CAdd electrons to the outside atoms.
  • DProduce octets of electrons by rearranging the electrons to form multiple bonds.
  • ELine the atoms up according to their atomic masses.

Q9:

Which of the following is the correct Lewis structure for Ga?

  • AGa
  • BGa
  • CGa
  • DGa
  • EGa

Q10:

In Lewis diagrams, what does each dot represent?

  • AA single positive charge
  • BA single inner-shell electron
  • CA single outer-shell electron
  • DA pair of electrons

Q11:

The Lewis dot structure for a sulfate ion gives sulfur a formal charge of zero with six bonds. Based on the structure and the Lewis dot theory, which of the following statements about the sulfur atom is false?

OS2OOO
  • ASulfur has a greater number of electron shells than oxygen.
  • BSulfur has more valence electrons than oxygen.
  • CThe sulfur disobeys the octet rule.
  • DSulfur is less electronegative than oxygen.

Q12:

Which of the following is the correct Lewis structure for a monomer of GaCl3?

  • A
    GaClClCl
  • B
    GaClClCl
  • C
    GaClClCl
  • D
    GaClClCl
  • E
    GaClClCl

Q13:

Which of the following is the correct Lewis structure for ClBBCl22?

  • A
    BClClBClCl
  • B
    BClBClClCl
  • C
    BClBClClCl
  • D
    BClClBClCl
  • E
    BBClClClCl

Q14:

Which of the following is the correct Lewis structure for CO2?

  • A
    OCO
  • B
    OOC
  • C
    COO
  • D
    COO
  • E
    COO

Q15:

In the reaction equation, what does the dot next to the sodium indicate?

+SodiumatomSodiumcationNaNa+e
  • AIt is bonded to another, small atom.
  • BIt is negatively charged.
  • CIt has a lone electron: it is a free radical.
  • DIt is positively charged.
  • EIt is unstable.

Q16:

In the equation shown, what do the two dots on the calcium atom indicate?

  • AIt is unstable.
  • BIt has two lone electrons; in separate orbitals: it is a diradical.
  • CIt has two lone pairs of electrons.
  • DIt is positively charged.
  • EIt is negatively charged.

Q17:

In the Lewis structure shown, X and Y represent different elements and all valence electrons of the atoms are shown. The molecule is stable and neutral, and Y is an element in the second period of the periodic table.

XXYX

What is the chemical symbol of element X?

  • ALi
  • BBe
  • CH
  • DHe
  • EF

What is the chemical symbol of element Y?

  • AB
  • BC
  • CF
  • DN
  • EO

Q18:

Which of the following is the correct Lewis structure for As3?

  • A
    As3
  • B
    As
  • C
    As3
  • D
    As3
  • E
    As

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