Lesson 5: The Nonmetals

CHEMISTRY

A Logical Progression

This textbook is an experiment designed to challenge
the traditional delivery of chemistry education while also
establishing a student-led, minimalistic approach to efficient,
in-depth mastery of the physical sciences.
Feel free to participate in the study.

First Edition V. R. RALPH

Nonmetals, small and complicated (Part 1).

What you should know...

Nonmetals tend to be in the gaseous state as they are highly _________.

Nonmetals are good _________ of heat and electricity.
Due to their median effective nuclear charge, nonmetals tend to share
electrons with one another in an effort to become _____________ with the noble gases.
The nonmetals can bond to produce molecular ions composed of two

or more atoms covalently bonded.
These ions are known as “polyatomic ions” and can ionically bond with metals or with Hydrogen.

14 15 16

|---------------- Nonmetals ----------------|

6 12.0107 7 14.0067 8 15.9994
C1086.5 +4 N1402.3 +5 O1313.9 +2
+3 +4 +1
2.55 +2 3.04 +3 3.44 -1
+1 +2 -2
Carbon -1 Nitrogen +1
-2 -1 Oxygen
1s22s22p2 -3 1s22s22p3 -2
-4 -3 1s22s22p4

15 30.97696 16 32.065
P1011.8 +5 S999.6 +6
Please note: +4 +5
Hydrogen is also 2.19 +3 2.58 +4
considered a ++21 +++123
nonmetal. -1 Sulfur -1
Phosphorus -2 -2
-3 [Ne] 3s23p4
[Ne] 3s23p3

1 1.00794 34 78.96
1312.0 Se941.0 +6
+1 ++24
H2.20 -1 2.55 -2

Hydrogen Selenium

1s1 [Ar] 3d104s24p4

Review and Apply:

1. Work with your group to analyze the data points provided in the periodic breakdown of the Halogens (above).
2. What trends do you see in the data (particularly in the manner in which these elements ionize)?
3. Draw the Lewis Structure, provide the electron configuration, and give all four quantum numbers of each
element.
4. Provide a schematic for how each of these elements could bond with themselves and each other element
in the group.
5. Try to form three molecular ions composed of only the nonmetals.
volatile, insultator, isoelectric 27

5.1 Properties of the Nonmetals

Properties of the Nonmetals: HH
• Dull appearance and brittle O
• Generally low density
• Poor conductors of heat and energy
• Can ionize into anions or cations
• Generally high ionization energy and electronegativity
• Variable melting and boiling points

Group 17 Atomic # Atomic Boiling Melting 1st Ionization Density Atomic
Mass Point (K) Point (K) (kJ/mol) (g/cm3) Radius (pm)
C 6
N 7 12.0107 4300 3800 1086.5 3.513 77
P 15 14.0067 77.36
O 8 30.97696 550 63.15 1402.3 1.251 75
S 16 15.9994 90.20 317.30 1011.8 1.823 106
Se 34 32.065 717.8
958 54.36 1313.9 1.429 73
78.96
388.36 999.6 2.08 102

494 941.0 4.81 116

•••O• C O•••• ••O••••C••••O•••• ••

Answer the following:
What trends do you see in the data? Why is carbon an outlier? Research the structure of graphite and diamond.
What state of matter are these elements at room temperature? Prove mathematically.
Determine how many covalent bonds each of the nonmetals (including Hydrogen) is capable of possessing.

28

5.2 Polyatomic Ions

Below is a list of the 16 most common polyatomic ions.
Memorize the formulas, names, and their charges.

Formula Name Charge Formula Name Charge

ClO3- Chlorate -1 NH4+ Ammonium +1
ClO2- Chlorite -1 OH- Hydroxide -1
ClO- Hypochlorite -1 CN- Cyanide -1
ClO4- Perchlorate -1 SCN- Thiocyanate -1
NO3- Nitrate -1 CrO42- Chromate -2
NO2- Nitrite -1 Cr2O72- Dichromate -2
SO42- Sulfate -2 PO43- Phosphate -3
SO32- Sulfite -2 PO33- Phosphite -3

Debate: How can two elements paired in different ratios produce the same ionic charge? (I.E. Sulfate/Sulfite)

Helpful Tips

Steps for Writing Lewis Dot Structure Using Prefixes & Suffixes as clues
for Heteroatomic Covalent Molecules: to Decifer Chemical Formulas:
1. Determine the central atom. 1. “Per-” = 4 oxygens.
2. Add up the # of valence electrons for each 2. “Hypo-” = 1 oxygen.
atom in the molecule. 3. “-ate” always has one more
3. Fill electrons to maximize octets. oxygen than “-ite”.
4. Place double or triple covalent bonds 4. Most polyatomics ending in
if necessary to complete the octets of all “-ate” also possess 4 oxygens.
atoms.
5. Confirm your oxidation numbers and the
overall charge of the molecule.

The sum of oxidation #’s ALWAYS = the charge of the ion.
Review: Illustrate a lewis dot structure for each of the 16 polyatomic ions and evaluate the statement above.

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5.3 Nomenclature of Covalent Molecules

Nomenclature Formula for Covalent Molecules

______ - _____________________ ______ - ________________________ - ______

(prefix) (name of the cation) (prefix) (name of the anion) (suffix)

Prefixes for covalent molecules only indicate the number of atoms for that particular “cation” or “anion”.

Please note: While covalent bonds do not involve ionization (since they share electrons), we
still name the more electronegative atom(s) the “anions” and the less electronegative atom(s) the “cations”.

Suffixes are “-ide” for monoatomic anions.

mono- di- tri- tetra- penta-
3 45
1 2
octa- none- deca-
hexa- hepta- 8 9 10

6 7

N2O5 -ide
CO2 -ide

Carbon Monoxide

Polyatomic ions tend to bond ionically with metals.
No prefixes are needed as the bonds formin ratios that result in an overall balanced compound.

If bound to a polyatomic ion,
the suffix matches that of the polyatomic ion.

(NH4)3PO4
Ammonium Sulfate

dinitrogen pentaoxide, carbon dioxide, ammonium phosphate, (NH4)2SO4 30

5.4 Covalent Bonds

The electrons shared in a covalent bond are not always shared equally.

Covalent Bond Polar Covalent Bond

H••H H•• ••F••••δ+ δ-

HH H Fδ+ δ-

••N••••••N•• δ- δ-H••••O••••H H••O••Hδ+ δ+ δ+ δ+δ- δ-
••N N••

Electrons with a higher electronegativity pull the electrons
towards them causing a “dipole” or partial charge (δ+ or δ-).

Research: Look into how hydrogen bonds occur and create a schematic in the above rectangle 31
as to how 10 water molecules would bond with one another.
Then draw a schematic for a glucose molecule.
How would these react together in aqueous solution?

5.5 Valence Shell Electron Pair Repulsion (VSEPR) Theory

Review: Electrons orbiting the nucleus of an atom _______ one another.

Valence Shell Electron Pair Repulsion (VSEPR) Theory suggests molecules assume 3D shapes that maximize
the amount of space between their electron groups.

Molecular Geometry: These shapes are determined by the number of
Linear I (2/0) electron groups surrounding the central atom.

OC O Bonding Groups Nonbonding Groups

180º 2 0
Electron Geometry: Linear (2)
Covalent Bonds Loan Pairs and
Single Electrons
(Single, Double, Triple;
they all count as 1)

Electron Geometry considers all of these groups equal.
Molecular Geometry accounts for nonbonding groups repeling

slightly more than bonding groups.

Molecular Geometry:
Linear II (2/3)

F Xe F

180º
Electron Geometry: Linear (2)

Bonding Groups Nonbonding Groups

2 3

repel 32

Molecular & Electron Geometry

Bonding Groups Nonbonding Groups Bonding Groups Nonbonding Groups

2 1 2 2

Molecular Geometry: H Molecular Geometry:
Bent I (2/1) O Bent II (2/2)

OO H
S
<109º
<120º Electron Geometry:
Electron Geometry:
Tetrahedral (4)
Trigonal Planar (3)

Bonding Groups Nonbonding Groups Bonding Groups Nonbonding Groups Bonding Groups Nonbonding Groups

3 0 3 1 3 2

F H F Br F
N F
B
FF HH

Molecular Geometry: Molecular Geometry: Molecular Geometry:
Trigonal Planar (3/0) Trigonal Pyramidal (3/1) T-Shaped (3/2)
120º
Electron Geometry: <109.5º <90º
Trigonal Planar (3) Electron Geometry: Electron Geometry:
Trigonal Bipyramidal (5)
ELECTRON GEOMETRY: Tetrahedral (4)

2- 3 - Trigonal 4- 5 - Trigonal 6-
Linear Planar Tetrahedral Bipyramidal Octahedral
33

Molecular & Electron Geometry (continued)

Bonding Groups Nonbonding Groups Bonding Groups Nonbonding Groups Bonding Groups Nonbonding Groups

40 41 42

HH FS F FF
C FF Xe

HH FF

Molecular Geometry: Molecular Geometry: Molecular Geometry:
Tetrahedral (4/0) Seesaw (4/1) Square Planar (4/2)
109.5º <90 - <120º 90º

Electron Geometry: Electron Geometry: Electron Geometry:
Tetrahedral (4) Trigonal Bipyramidal (5) Octahedral (6)

Bonding Groups Nonbonding Groups Bonding Groups Nonbonding Groups Bonding Groups Nonbonding Groups

50 51 60

Molecular Geometry: Molecular Geometry: Molecular Geometry:
Trigonal Bypyramidal (5/0) Square Pyramidal (5/1) Octahedral (6/0)

Cl F F
F
Cl P Cl F F F
Cl Cl Br F S F
F
F
F

90-120º <90º 90º
Electron Geometry: Electron Geometry: Electron Geometry:
Trigonal Bipyramidal (5)
Octahedral (6) Octahedral (6)

34

Review: Molecular & Electron Geometry

Orbital Bonding Nonbonding Electron Molecular Angle(s) Example
Hybridization Groups Groups Geometry Geometry Molecule

sp 2 0 Linear Linear I 180º CO2
SO2
sp2 2 1 Trigonal Bent I <120º H2O
sp3 2 Planar XeF2
BF3
2 Tetrahedral Bent II <109º NH3
BrF3
sp3d 2 3 Trigonal Linear II 180º CH4
Bipyramidal SF4
Trigonal Trigonal XeF4
sp2 3 0 Planar Planar 120º PCl5
BrF5
sp3 3 1 Tetrahedral Trigonal <109.5º SF6
Pyramidal
Trigonal
sp3d 3 2 Bipyramidal T-Shaped <90º

sp3 4 0 Tetrahedral Tetrahedral 109.5

sp3d 4 1 Trigonal Seesaw <90º -
Bipyramidal <120º
Square
sp3d2 4 2 Octahedral Planar 90º

sp3d 5 0 Trigonal Trigonal 90º-120º
Bipyramidal Bipyramidal
Square
sp3d2 5 1 Octahedral Pyramidal <90º

sp3d2 6 0 Octrahedral Octahedral 90º

Orbital Hybridization describes bonding atoms from the perspective of the central atom.
sMheatpheandees(cCrHib4)eids sp3 hybridized, meaning the orbitals surrounding the central atom have a
as 25% s-orbital and 75% p-orbital (or a hybrid of the two 3D orbitals).

Review:

1. Describe the shape of an sp3d2 hybridizied orbital in percentages.
2. Draw the lewis structure, provide the molecular geometry, electron geometry, and orbital
hybridization of the following molecules: PF3, OF2, IBr4-, SeF6, H3CNH2, NF3, CIF3, HNNH, BrCl5,
and SO2.
35

5.6 Major Types of Chemical Reactions

Chemists can predict the outcomes of chemical reactions by determining the reaction type.
Just as we did in our discussion of ionic bonding, double displacement reactions tend to
occur between ionic compounds.

Double Displacement Reactions Single Displacement Reactions

AB+CD AD+CB AB+C A+CB

Two ions are displaced (or moved). Only one ion is displaced.

PrNedaiCclt+thAegPNrOo3d, auncdtsM: NgaCOl2H++AClBarB3r2, PredicatntdheMPgr(oCd2Hu3cOt2s):2N+aLNi+O3 + K+

CxHy + O2 Combustion Reactions
H2O + CO2 + Energy
A high energy hydrocarbon reacts with a molecular of oxygen to result in
simpler, lower energy products such as water and carbon dioxide.

Predict the Products: CH4 + O2 and C3H8 + O2

Synthesis Reactions Decomposition Reactions

A+B AB AB A+B

Two reactants combine consuming Two reactants combine consuming
energy to form a single product. energy to form a single product.

Predict the Products: Na + Cl2 and Zn + I2 Predict the Products: H2O2 and NH4OH

In future chemistry courses, you will learn of two more reaction types involving the
exchanges of protons (Acid/Base Reactions) and electrons (Electrochemistry Reactions).

Review: 36
1. Fill in the missing parts of the equations below:
2. Idenabct...if_CCy_aHt_Sh4_Oe+_4t_O+y+p2_-e__->_o___f___r_e___a___c_-_t-i_->o-_>nP+bCfoO_ar(_2Oa_-H_c_)(2_a+_boMvgeS).O4

Molecular & Electron Geometry

Bonding Groups Nonbonding Groups Bonding Groups Nonbonding Groups

2 1 2 2

Molecular Geometry: H Molecular Geometry:
Bent I (2/1) O Bent II (2/2)

OO H
S
<109º
<120º Electron Geometry:
Electron Geometry:
Tetrahedral (4)
Trigonal Planar (3)

Bonding Groups Nonbonding Groups Bonding Groups Nonbonding Groups Bonding Groups Nonbonding Groups

30 3 1 3 2

F H F Br F
N F
B
FF HH

Molecular Geometry: Molecular Geometry: Molecular Geometry:
Trigonal Planar (3/0) Trigonal Pyramidal (3/1) T-Shaped (3/2)
120º
Electron Geometry: <109.5º <90º
Trigonal Planar (3) Electron Geometry: Electron Geometry:
Trigonal Bipyramidal (5)
ELECTRON GEOMETRY: Tetrahedral (4)

2- 3 - Trigonal 4- 5 - Trigonal 6-
Linear Planar Tetrahedral Bipyramidal Octahedral
33