Lewis Dot Diagrams Practice

Here are a variety of Lewis Dot Diagrams. Some are correct, some are wrong. Look, think, click to check if you were doing good thinking
or if it was incorrect thinking. If you were incorrect, think hard about the answers and make sure you understand why you were wrong.

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Vocabulary

allotrope

pure forms of elements,
with different physical structures,
and different physical properties.

Example: oxygen and ozone

This is correct because arsenic has
a 2-8-18-5 electron configuration.

It has 5 electrons in it's valence orbital.

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Vocabulary

isotopes

chemically identical atoms with
different number of neutrons
and different masses.

This is correct because argon has a 2-8
for its electron configuration.

It has 8 electrons in it's valence orbital.

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Vocabulary

allotropes more examples

carbon atoms, graphite, diamonds,
buckminister fullerenes (or bucky balls)

This is correct because helium has a 2
for its electron configuration.

It has 2 electrons in it's valence orbital.

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Vocabulary

valence orbital

the outermost orbital of the atom

This is correct because bromine has a 2-8-18-7
for its electron configuration.

It has 7 electrons in it's valence orbital.

Br⁺¹

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Vocabulary

valence electrons

Electrons in the outermost orbital
of the atom

This is incorrect because bromine has a 2-8-18-7
for its electron configuration.
It makes a -1 anion, not a cation

It has 7 electrons in it's valence orbital.

PCl₃

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Vocabulary

inner electrons

Electrons in the inner orbitals which do not participate in bonding. These are also called shielded electrons

This is incorrect because all three of the chlorine atoms have lost 3 pairs of unshared electrons each.

F⁺¹

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Vocabulary

PV = C

pressure X volume of any gas sample
is equal to the gas constant
FOR THAT GAS SAMPLE.
It will have weird units,
like psi·ml, or kPa·cm³

This is in correct because flourine makes a -1 anion, and anions have 8 electron dots in their brackets.

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Vocabulary

STP

standard pressure AND
standard temperature,

from table A

This is correct because magnesium has a 2-8-2 electron configuration, with 2 valence electrons.

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Vocabulary

ionic bond

a strong bond between positive cations
and negative anions.
It's formed by the transfer of electrons.

This is correct because neon has a 2-8 electron configuration. It has 8 valence electrons.

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Vocabulary

covalent bond

a bond between 2 or more nonmetals,

they share electrons.

This is correct because oxygen has a 2-6 electron configuration, with 6 valence electrons.

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Vocabulary

ionic bonds can never be single, double or triple. They just are cations and anions attracted together.

This is in correct because phosphorous atoms have five valence electrons. Phosphide anions are -3, but the dot diagram needs brackets.

C₂H₄ x

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Vocabulary

single covalent bond

2 atoms each sharing one pair of electrons.
Both atoms put ONE electron up.

This is incorrect because all the carbons NEED octets, and would make a double covalent bond between them.

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Vocabulary

hydrogen bonds

intermolecular attraction due to a large electronegativity difference only possible
with hydrogen as one atom in the bond.

This is correct because phospohorous has an electron configuration of 2-8-5, with 5 valence electrons.

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Vocabulary

van der Waal's forces

two kinds of weak inter-moleclar forces,
called dipole interaction and the
electron dispersion force.

This is correct because aluminum has a 2-8-3 electron configuration, and has 3 valence electrons.

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Vocabulary

dipole interaction

intermolecular force of attraction due
to permanent + and - sides of a covalent bond,
caused by a difference in
electronegativity values

This is correct because iodine has a 2-8-18-18-7
electron configuration, and has 7 valence electrons.

K⁺¹

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Vocabulary

electron dispersion force

weak attraction between atoms or molecules
due to the temporary and instantaneous positioning of the electrons, which
are in constant motion.

This is correct because the potassium just
one valence electron, which it loses when it
becomes a +1 cation.

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Vocabulary

unshared pair of electrons

when an atom has electrons in its valence orbital that are NOT involved in a bond,
they are called UNSHARED pairs of electrons

This is correct because potassium has an
electron configuration of 2-8-8-1
and has just one valence electron.

CO₂

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Vocabulary

polar covalent bonds

due to a difference in electronegativity values. The greater the difference,
the greater the bond polarity.

This is correct because all three of the atoms
have to get an octet. There are 2 double polar
covalent bonds here.

CH₄

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Vocabulary

non-polar covalent bond

when two nonmetallic atoms with the
same electronegativity values bond.
Neither "wants" the electrons more,
so they share the electrons perfectly,
without creating a + or - side.

This is correct because carbon gains 4 electrons from
four hydrogen atoms to get an octet.
Each hydrogen gets an electron from carbon,
to fill its little orbital.

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Vocabulary

inner electrons

Electrons in the inner orbitals which do not participate in bonding. These are also called shielded electrons

This is correct because fluorine has an electron configuration of 2-7. with 7 valence electrons

HI x

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Vocabulary

triple covalent bond

when 2 nonmetals bond together sharing
3 pairs of electrons. Example is N₂ or
|when 2 carbon atoms bond together in C₂H₂.

This is in correct because all iodine is missing three pairs of unshared electrons.

N₂

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Vocabulary

dipole arrow

a simple arrow showing "where the electron
is going" and a + sign, indicating where
the electron is no longer.
Missing electrons mean missing negative charge which is "positive".

This is correct because each nitrogen has an octet,
only possible with this triple nonpolar covalent bond.

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Vocabulary

radial symmetry

when something can be cut at any angle,
through the middle and you get 2 equal halves. When molecules have radial symmetry they
are nonpolar molecules.

This is correct because sulfur has an electron configuration of 2-8-6, with 6 valence electrons.

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Vocabulary

bilateral symmetry

the sort of symmetry a human body has,
and so does the water molecule.
Unless a molecule has radial symmetry
it's a polar molecule.

This is correct because they share one pair of
electrons to make a single polar covalent bond,
and iodine shows all of its octet.

HCl

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Vocabulary

double ionic bond

There is NO SUCH THING as a single,
double or triple ionic bond.
Ions are attracted only because of the
cation-anion attraction.

This is correct because both atoms have full orbitals,
and chlorine has the full octet.
They make a single polar covalent bond.

F₂

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Vocabulary

brackets

are required for all Lewis dot diagrams containing any ions.
They must show charge as well.

This is correct because both of the fluorine atoms
have full octets, and they share a
single nonpolar covalent bond.

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Vocabulary

non polar molecules

must have radial symmetry.

Even if the bonds are polar, they offset
each other due to shape.

This is correct because all of the atoms show full octets, and they each share a single polar covalent bond.

H₂O x

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Vocabulary

inner electrons

Electrons in the inner orbitals which do not participate in bonding. These are also called shielded electrons

This is incorrect because the hydrogen atoms
both have octets (too many electrons)
and the oxygen does not (too few).

CO₂ x

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Vocabulary

resonance

when bonds alternate back and forth
very quickly. In ozone this causes
intermediate bonds, in between single
and double in strength.

This is in correct because carbon does not have
an octet, and each oxygen seems bonded to
the carbon, but oxygen are not putting any
electrons into the mix.

F₂ x

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Vocabulary

coordinate covalent bond

a special bond seen in CO, when the carbon
and oxygen share 2 pair of electrons to
make a double polar covalent bond
PLUS
oxygen "lends" 2 electrons to the center,
to let carbon access them so it too can
have an octet.

This is in correct because the fluorine atoms do not
have enough valence electrons
(they have 5 each instead of 7), and,
they are making a triple covalent bond
(like nitrogen would have).

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Vocabulary

electronegativity

the tendency for an atom to get the electron
in a bonding situation. The difference
between the electronegativity values
determines bond polarity.

This is correct because nitrogen has an electron configuration of 2-5, with five valence electrons.

Ca⁺²

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Vocabulary

Lewis Dot Diagram

A simple drawing method showing valence electrons of atoms, ions, or compounds.
It helps kids count to 2 or 8.

This is correct because when calcium loses its
2 valence electrons and becomes a +2 ion,
the Lewis Dot diagram shows the 'new' valence orbital,
in this case, empty.

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Vocabulary

van der Waal's forces

include both dipole attractions
as well as electron dispersion forces.

This is correct because chlorine has 7 valence electrons, and they would be in three pairs plus one alone.

N₂ x

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Vocabulary

electronegativity difference

the greater the difference between two atoms
electronegativity values, the greater
the bond polarity they exhibit.

This is incorrect because when two nitrogen atoms
bond together they each only have 5 valence electrons,
and need to make a triple nonpolar covalent bond
to both get octets.

Li x

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Vocabulary

transfer of electrons

indicates an ionic bond, when a
cation "loses" electrons to the anion,
which "gains" them. Both end up with
full outer valence orbitals.

This is incorrect because even though up to 8 electrons fit into a Lewis Dot diagram, you must only show the valence electrons. Lithium has a 2-1 configuration, it should only have one dot.

He⁺² x

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Vocabulary

noble gases

do not bond with other atoms, nor form ions. These atoms have full outer valence orbitals, they are "set", and do not make bonds.

This is incorrect because this shows a
helium +2 cation. Helium would NEVER lose electrons
(or gain them). It's a noble gas, and will
not make any sort of bonds with any other atoms.