Transcript Nonmetals & Metalloids Nonmetals • Nonmetals are located to the right of the stair step line on the periodic table except for hydrogen • Nonmetals.

Nonmetals & Metalloids
Nonmetals
• Nonmetals are located to the right of the stair
step line on the periodic table except for
hydrogen
• Nonmetals are usually gases or brittle solids
• Nonmetals are poor conductors of heat and
electricity because the outer electrons are
strongly attracted to the nucleus
Hydrogen
• It is an exception to location on
the periodic table because it
shares chemical properties with
the alkali metals
• 90 percent of all atoms in the
universe are hydrogen
• Hydrogen is highly reactive
• Hydrogen can be found as a
diatomic molecule, or two
molecules of the same type joined
together
Halogens – Group 17
• Halogens are very reactive in their elemental
form and are only found in nature in
compounds
• They contain seven electrons in their outer
energy level
• In their gaseous state, halogens form diatomic
molecules of distinctive colors: Chlorine –
greenish yellow, Bromine – reddish orange,
Iodine - violet
• Fluorine is the most chemically active element
• Bromine is the only nonmetal that is a liquid at
room temperature
Uses of Halogens
• Halogens are used in halogen
lamp bulbs to give them a longer
life
• Chlorine and bromine compounds
are used to disinfect drinking
water or pool water
• Fluoride compounds are used in
toothpaste to prevent tooth decay.
• Iodine is essential to you diet for
the production of the hormone
thyroxin.
The Noble Gases
• The noble gases exist as isolated atoms
• They are the most stable elements
because their outer energy levels are filled
• There are no naturally occurring noble
gas compounds, but compounds of xenon
and krypton with fluorine have been
created in laboratories.
Uses of Noble Gases
• Their inability to react is what
makes noble gases useful
• They are used as components
of high performance lightbulbs
and neon lighting
• High powered lasers used in
light shows or for medical
purposes use noble gases.
• Helium is used in blimps and
balloons due to it’s low density
Metalloids
• Metalloids are the elements that
border the stair step on the periodic
table except for aluminum and
polonium
• They have properties of both metals
and nonmetals
• Metalloids are also known as
semiconductors due to the fact that
they can conduct heat and electricity
under certain conditions
• They are usually metallic looking
solids that are brittle
Uses of Metalloids
• The most common use of metalloids is in
electronics in the form of semiconductors or
microchips
• They are also used to form alloys with metals to
enhance their properties
Mixed Groups
• The remaining groups on the periodic table are
all mixed groups, they contain metals,
nonmetals, and metalloids
• They have similar chemical properties but
dissimilar physical properties
Some Important Nonmetals
• Carbon is important to all life on Earth
• Silicon is the second most abundant element in
the Earth’s crust after oxygen
• Silicon and Carbon both occur in different
allotropes – different forms of the same element
Some Important Nonmetals
• Nitrogen is the main component of the
air we breath
• Nitrogen and Phosphorus are used to
make fertilizers
• They are also the components of many
organic compounds including DNA
• Phosphorus is also used to make
matches, and certain forms of it glow
when exposed to oxygen
• Oxygen is used by most life on Earth
for respiration and exists in the air as
diatomic molecules
Synthetic Elements
• Not all elements found on the
periodic table are found naturally
• Some elements are found only by
creating them in a laboratory
• With the exception of technetium
and promethium, all synthetic
elements have a 93 or more
protons.
• These elements are created by
smashing existing elements
together in a particle accelerator
Transuranium Elements
• All elements on the periodic table with 93 or
more protons are called transuranium elements
and are synthetically created
• All are unstable, and many disintegrate quickly
• It is theorized that stable synthetic elements may
exist that can overcome the enormous repulsion
forces of the protons