Metalloids are elements that have properties of both metals and non-metals. They are located between metals and non-metals in the periodic table. The seven metalloids are boron, silicon, germanium, arsenic, antimony, tellurium, and polonium. Metalloids show mixed properties such as being shiny or dull, behaving as metals or non-metals depending on what they react with, and some act as semiconductors. Common uses of metalloids include boron in glass and insecticides, silicon in electronics and cement, and germanium in lenses and electronics.
2. What are metalloids?
Metalloids are the elements which possess the qualities of metals as well as
non-metals, hence they are also known as semimetals. Metalloids in the
periodic table are placed between the metals and the non-metals and are
located in a step-like structure. Hence we can say that the periodic table is
divided into three types of elements: metals, non-metals and metalloids.
All, there are seven metalloids which are placed from the 13th to
the 16th group of the periodic table.
They are: Boron (B), Silicon (Si), Germanium (Ge),
Arsenic (As), Antimony (Sb), Tellurium (Te), and Polonium
(Po).
3. Properties of Metalloids
Metalloids show mixed properties of metals as well
as non-metals.
• They can be shiny or dull in appearance and brittle in
nature.
• They behave as non-metals when they react with metals
and behave as metals when they react with non-metals.
• They are amphoteric oxides which means they can
behave as basic oxides as well as acidic oxides.
• Boron, silicon and germanium behave as
semiconductors.
• All the metalloids have different melting and boiling
points.
• They are ductile and can be bent into pipes.
• Some of the metalloids look like metals, solid, and tough.
4. Boron (B)
• Boron is used in the production of borosilicate glass. These glasses have a
high resistance to thermal shock which causes normal glasses to break.
• It is used in the form of sodium tetra borate to insulate fiberglass.
• They are used as control rods in the nuclear reactors in the form of boron
carbide shields.
• It is present in the strongest type of magnet: the neodymium magnet. This
magnet is used in the CD and DVD players, cell phones, Magnetic
Resonance Imaging (MRI) machines, etc.
• It is used in making many cleaning products like detergents and bleach.
• It is very widely used in killing ants, fleas, cockroaches, and other small
insects.
• Boron in the form of sodium borate, hinders fire and hence it is used in
plastics and rubbers.
• As it possesses metallic properties also, it is used in coating substances to
increase their strength and hardness.
5. Silicon (Si)
• Silicon is known for its semiconductor properties. It is used in many
electronic devices like computers, transistors, solar cells, LCD screens, to
control the flow of electricity.
• Silicon in the form of silicon dioxide and silica are used in the
manufacture of brick, concrete, and cement.
• Silicon is used as putty which is formed with the help of boric acid and
silicon oil.
• It is used in high temperature waxes and greases.
• It is used in making explosives and fireworks.
• Alloys of silicon and aluminum are used in making cast parts for cars and
other automobiles.
• They are also used in making
pottery and enamel.
6. Germanium (Ge)
• Germanium has a high refractive index, hence it is used in wide-angle camera
lenses, microscope lenses, etc.
• Germanium also behaves as a semiconductor, hence it is also used in many
electronic devices like computers, calculators, transistors, etc.
• It behaves as a catalyst in many polymerization reactions.
• With phosphor it is used in fluorescent lamps, metallurgy and chemotherapy.
• It is used in fiber optics and infra-red optics and in infrared spectroscopy.
• Germanium was previously used to treat anemia, but later it was found that it is
responsible for many health hazards. Today propagermanium or organic
germanium or beta-carboxyethylgermanium sesquioxide are used with
complementary medicines, and are helpful in boosting the immune system of
cancer patients.
• It is also used to aid in treatment of AIDS, heart diseases and arthritis.
7. Arsenic (As)
Arsenic-74 is an isotope which is believed to be more effective than iodine in taking
images and locating tumors.
It is used in preserving wood from various bacteria, fungi and insects.
It was also used in various pesticides and herbicides but is rarely used nowadays.
It is also used as a semiconductor in electronic devices.
It is medically used in treating cancer and acute promyelocytic leukemia.
It is mixed with animal food to protect them from various diseases.
8. Antimony (Sb)
• The most important use of antimony is in the making of flame retardants. It is
used in aircraft, automobile seat covers, light aircraft engine covers, etc.
• It is used with lead to increase the hardness and mechanical strength of lead
which is used in acid batteries.
• Its alloys are also used in making bullets, cable sheathing, etc.
• It is used as a catalyst in the production of many polymers.
• It is also used as a semiconductor in electronic devices.
• It is used as a friction coefficient in making automobile brakes and pads.
• It is also used in the safety equipment in nuclear reactors.
• Antimony drugs are used in many medications for treating a number of diseases.
9. Tellurium (Te)
• Tellurium is used to increase the ductility of stainless steel and copper.
• Tellurium is also present in cast iron alloys to help regulate the temperature.
• It reduces the rate of corrosion in the metal.
• It behaves as a semiconductor and is used in many electronic applications.
• It is also very effective in solar cell panels as a semiconductor.
• Tellurium with zinc forms a gamma-ray detector and with mercury it makes for
an infrared detector.
• It is used in making ceramics, tinting glasses, blasting caps, etc.
• It is used in reducing engine knocking.
10. Polonium (Po)
• Alpha particles of radioactive polonium (210Po) are used to release neutrons from
beryllium.
• They are used in the thermoelectric cells of artificial satellites because of their
ability to release large amounts of energy.
• It is also used in paper rolling machines, spinning synthetic fibers, etc., in order to
eliminate static electricity.
• It is used in the radioisotope thermoelectric generator in the remote areas such as
lighthouses.
