Nonmetals and Metalloids
Periodic Table of Elements
Matter: Properties and Changes
Warm up
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In your notebook answer the following exercise:
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Find the element copper (Cu) in the periodic table, what can you infer
about copper’s properties and explain how its position in the periodic
table helps identify its properties.
Lesson Objectives
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Describe the properties of nonmetals.
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Tell how metalloids are useful.
Nonmetals
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Nonmetals are elements that lacks most of the properties of metals.
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Most nonmetals are poor conductors of electricity and heat and are
reactive with other elements.
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Many of the nonmetals are common elements on Earth.
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Nitrogen
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Oxygen
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Carbon
Physical Properties of Nonmetals
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Ten of the 16 nonmetals are gases at room temperature.
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nitrogen and oxygen
Others are solid nonmetals are dull and brittle.
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carbon, phosphorus, and sulfur
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Bromine is the only nonmetal that is liquid at room temperature.
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Nonmetals usually have lower densities than metals, and are poor
conductors of heat and electricity.
Chemical Properties of Nonmetals
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Except for Group 18, most nonmetals readily form compounds with
other elements.
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Many metals and nonmetals react with each other. Their atoms
usually gain or share electrons when they react to other atoms.
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Nonmetals can also form compounds with other nonmetals by
sharing electrons.
FAmilies of Nonmetals
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Carbon Family
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Nitrogen Family
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Oxygen Family
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Halogen Family
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Noble Gases
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Hydrogen
Carbon FAmily
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The elements in Group 14.
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They gain, lose, or share four
electrons when reacting with other
elements.
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Carbon is the only nonmetal
element in the group and play an
important role in the chemistry of
life.
Nitrogen Family
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The elements in Group 15.
The two nonmetals in this group
are nitrogen and phosphorus.
These nonmetals usually gain or
share three electrons when reacting
with other elements.
Nitrogen is an element that occurs
in nature as a molecule formed
from two nitrogen atoms bonded
together.
A molecule that is made up of two
identical atoms is a diatomic
molecule.
Oxygen Family
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The elements in Group 16.
The three nonmetals in this group are
oxygen, sulfur, and selenium.
These atoms typically gain or share
two electrons in a reaction.
The oxygen is highly reactive and it
can combine with almost every other
element. It is the most abundant
element in the Earth’s crusg. We
breathe is O2 and the ozone is O3.
Sulfur is the other common nonmetal
in this family.
Halogen Family
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The elements in Group 17 are the most
reactive elements.
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All but one of the halogens are
nonmetals.
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A halogens atom typically gain or
shares one electron.
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Halogen elements are dangerous,
many of the compounds that halogens
form are quite useful.
Noble Gases
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The elements in Group 18 do not
ordinarily form compounds because the
atoms of these elements do not gain,
lose, or share electrons.
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Usually unreactive
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All the noble gases exist in Earth’s
atmosphere, but only in small amounts.
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Because they are so unreactive, they
were not discovered until the late 1800s.
Hydrogen
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Is the simplest element
Its atoms contain one proton and one electron.
Because hydrogen’s chemical properties are so different from the
other elements, it cannot be grouped into a family.
Hydrogen makes up more than 90 percent of the atoms in the
universe, it makes up only 1 percent of the mass of found on Earth’
s crust, oceans, and atmosphere.
Hydrogen is rarely found on Earth as a pure element.
Most hydrogen is combined with oxygen in water (H2O).
Metalloids
Boron, silicon, germanium, arsenic, antimony, tellurium, polonium, astatine
Metalloids
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On the border between the metals and nonmetals are seven
elements called metalloids.
Metalloids have some of the characteristics of metal and some of
nonmetals.
The most useful property of the metalloids is their varying ability to
conduct electricity. Some are used to make semiconductors.
Semiconductors are substances that under some conditions can
carry electricity, and under other conditions cannot carry electricity.
Some semiconductors are used to make computer chip, transistors,
and lasers.