Elements

1
Elements
Hydrogen
Number of Protons
1 Neutrons
0 Electrons
1 Boiling point
-252 Freezing point
-259 State at room temperature gas
Brief description hydrogen is the lightest
element. It is by far the most abundant element
in the universe and makes up about about 90 of
the universe by weight. Hydrogen as water (H2O)
is absolutely essential to life and it is present
in all organic compounds. Hydrogen is the
lightest gas. Hydrogen gas was used in
lighter-than-air balloons for transport but is
far too dangerous because of the fire risk
(Hindenburg). It burns in air to form only water
as waste product and if hydrogen could be made on
sufficient scale from other than fossil fuels
then there might be a possibility of a hydrogen
economy.
2
Elements
Helium
Number of Protons
2 Neutrons
2 Electrons
2 Boiling point
-268 Freezing point
-272 State at room temperature gas
Brief description helium is one of the so-called
noble gases. Helium gas is an unreactive,
colourless, and odourless gas. Helium is
available in pressurised tanks. Helium is the
second most abundant element in the universe
after hydrogen. Helium is used in lighter than
air balloons and while heavier than hydrogen, is
far safer since helium does not burn. Speaking
after breathing an atmosphere rich in helium
results in a squeaky
3
Elements
Lithium
Number of Protons
3 Neutrons
4 Electrons
3 Boiling point
1347 Freezing point 180 State
at room temperature solid
Brief description lithium is a Group 1 element
Group 1 elements are called "alkali metals".
Lithium is a solid only about half as dense as
water and lithium metal is the least dense metal.
A freshly cut chunk of lithium is silvery, but
tarnishes in a minute or so in air to give a grey
surface. Lithium is mixed (alloyed) with
aluminium and magnesium for light-weight alloys,
and is also used in batteries, some greases, some
glasses, and in medicine.
4
Elements
Boron
Number of Protons
5 Neutrons
5 Electrons
5 Boiling point
2550 Freezing point
2300 State at room temperature solid
Brief description boron is a Group 13 element
that has properties which are borderline between
metals and non-metals (semi metallic). It is a
semiconductor rather than a metallic conductor.
Chemically it is closer to silicon than to
aluminium, gallium, indium, and thallium.
5
Elements
Carbon
Number of Protons
6 Neutrons
6 Electrons
6 Boiling point
3440 Freezing point
4827 State at room temperature solid
Brief description carbon is a Group 14 element
and is distributed very widely in nature. It is
found in abundance in the sun, stars, comets, and
atmospheres of most planets. Carbon is found free
in nature in three allotropic forms amorphous,
graphite, and diamond. Graphite is one of the
softest known materials while diamond is one of
the hardest. Carbon, as microscopic diamonds, is
found in some meteorites. Natural diamonds are
found in ancient volcanic "pipes" such as found
in South Africa. Diamonds are also recovered from
the ocean floor off the Cape of Good Hope.
6
Elements
Oxygen
Number of Protons
8 Neutrons
8 Electrons
8 Boiling point
-182 Freezing point -
218 State at room temperature gas
Brief description oxygen is a Group 16 element.
While about one fifth of the atmosphere is oxygen
gas, the atmosphere of Mars contains only about
0.15 oxygen. Oxygen is the third most abundant
element found in the sun, and it plays a part in
the carbon-nitrogen cycle, one process
responsible for stellar energy production. About
two thirds of the human body, and nine tenths of
water, is oxygen. The gas is colourless,
odourless, and tasteless. Liquid and solid oxygen
are pale blue.
7
Elements
Fluorine
Number of Protons
9 Neutrons 10
Electrons
9 Boiling point
-188 Freezing point -
219 State at room temperature gas
Brief description fluorine is a Group 17
element. Fluorine is the most electronegative and
reactive of all elements. It is a pale yellow,
corrosive gas, which reacts with practically all
organic and inorganic substances. Finely divided
metals, glass, ceramics, carbon, and even water
burn in fluorine with a bright flame. It is not
uncommon to see fluorine spelled incorrectly as
flourine.
8
Elements
Sodium
Number of Protons
11 Neutrons
12 Electrons
11 Boiling point
882 Freezing point 97 State
at room temperature solid
Brief description sodium is a Group 1 element
which are often referred to as the "alkali
metals". Sodium salts impart a characteristic
orange/yellow colour to flames and orange street
lighting is orange because of the presence of
sodium in the lamp. Soap is generally a sodium
salt of fatty acids. The importance of common
salt to animal nutrition has been recognized
since prehistoric times. The most common compound
is sodium chloride, (table salt).
9
Elements
Magnesium
Number of Protons
12 Neutrons
12 Electrons
12 Boiling point
1090 Freezing point 648 State
at room temperature solid
Brief description magnesium is a greyish-white,
fairly tough metal. Magnesium is the eighth most
abundant element in the earth's crust although
not found in it's elemental form. It is a Group 2
element Group 2 elements are called alkaline
earth metals. Magnesium metal burns with a very
bright light. Magnesium is an important element
for plant and animal life. The adult human daily
requirement of magnesium is about 0.3 g day-1
10
Elements
Potassium
Number of Protons
19 Neutrons
20 Electrons
19 Boiling point
774 Freezing point 63 State at
room temperature solid
Brief description potassium is a metal and is
the seventh most abundant and makes up about 1.5
by weight of the earth's crust. Potassium is an
essential constituent for plant growth and it is
found in most soils. It is also a vital element
in the human diet. Potassium is never found free
in nature, but is obtained by electrolysis of the
chloride or hydroxide. It is one of the most
reactive and electropositive of metals and, apart
from lithium, it is the least dense known metal.
It is soft and easily cut with a knife. It is
silvery in appearance immediately after a fresh
surface is exposed. .
11
Elements
Calcium
Number of Protons
20 Neutrons
20 Electrons
20 Boiling point
1484 Freezing point 839 State
at room temperature solid
Brief description calcium as the element is a
grey silvery metal. The metal is rather hard.
Calcium is an essential constituent of leaves,
bones, teeth, and shells. Calcium is the fifth
most abundant element in the earth's crust and
makes up more than 3 of the crust. Calcium does
not occur as the metal itself in nature and
instead is found in various minerals including as
limestone, gypsum and fluorite. Stalagmites and
stalactites contain calcium carbonate (CaCO3).
Calcium carbonate is the basis of the cement
industry.
12
Elements
Iron
Number of Protons
26 Neutrons
30 Electrons
26 Boiling point
2750 Freezing point 1535 State
at room temperature solid
Brief description Iron is a relatively abundant
element in the universe. It is found in the sun
and many types of stars in considerable quantity.
Iron nuclei are very stable. Iron is a vital
constituent of plant and animal life, and is the
key component of haemoglobin. The pure metal is
not often encountered in commerce, but is usually
alloyed with carbon or other metals. The pure
metal is very reactive chemically, and rapidly
corrodes, especially in moist air or at elevated
temperatures. Any car owner knows this. Iron
metal is a silvery, lustrous metal which has
important magnetic properties.
13
Elements
Copper
Number of Protons
29 Neutrons
35 Electrons
29 Boiling point
2567 Freezing point 1083 State
at room temperature solid
Brief description Copper is one of the most
important metals. Copper is reddish with a bright
metallic lustre. It is malleable, ductile, and a
good conductor of heat and electricity (second
only to silver in electrical conductivity). Its
alloys, brass and bronze, are very important. Gun
metals also contain copper. Apparently the reason
that policemen in the USA are nicknamed cop" or
copper" is to do with their uniforms which used
to have copper buttons.
14
Elements
Zinc
Number of Protons
30 Neutrons
35 Electrons
30 Boiling point
907 Freezing point 419 State
at room temperature solid
Brief description Zinc-deficient animals require
50 more food to gain the same weight of an
animal supplied with adequate amounts of zinc.
Zinc is not particularly toxic and is an
essential element in the growth of all animals
and plants. Plating thin layers of zinc on to
iron or steel is known as galvanising and helps
to protect the iron from corrosion.
15
Elements
Nitrogen
Number of Protons
7 Neutrons
7 Electrons
7 Boiling point
-209 Freezing point -195 State
at room temperature gas
Brief description Nitrogen is a Group 15
element. Nitrogen makes up about 78 of the
atmosphere by volume but the atmosphere of Mars
contains less than 3 nitrogen. The element
seemed so inert that Lavoisier named it azote,
meaning "without life". However, its compounds
are vital components of foods, fertilizers, and
explosives. Nitrogen gas is colourless,
odourless, and generally inert. As a liquid it is
also colourless and odourless.
16
Elements
Aluminium
Number of Protons
13 Neutrons
14 Electrons
13 Boiling point
2467 Freezing point 660 State
at room temperature solid
Brief description pure aluminium is a
silvery-white metal with many desirable
characteristics. It is light, nontoxic (as the
metal), nonmagnetic and nonsparking. It is
somewhat decorative. It is easily formed,
machined, and cast. Pure aluminium is soft and
lacks strength, but alloys with small amounts of
copper, magnesium, silicon, manganese, and other
elements have very useful properties. Aluminium
is an abundant element in the earth's crust, but
it is not found free in nature.
17
Elements
Silicon
Number of Protons
14 Neutrons
14 Electrons
14 Boiling point
2355 Freezing point 1410 State
at room temperature solid
Brief description silicon is present in the sun
and stars and is a principal component of a class
of meteorites known as aerolites. Silicon makes
up 25.7 of the earth's crust by weight, and is
the second most abundant element, exceeded only
by oxygen. It is found largely as silicon oxides
such as sand (silica), quartz, rock crystal,
amethyst, agate, flint, jasper and opal. Silicon
is found also in minerals such as asbestos,
feldspar, clay and mica.
18
Elements
Phosphorus
Number of Protons
15 Neutrons
16 Electrons 15 Boiling
point 280 Freezing point
44 State at room temperature solid
Brief description It is an essential component
of living systems and is found in nervous tissue,
bones and cell protoplasm. Phosphorus exists in
several forms including white (or yellow), red,
and black (or violet). White phosphorus has two
modifications. Ordinary phosphorus is a waxy
white solid. When pure, it is colourless and
transparent. It is insoluble in water. It catches
fire spontaneously in air.
19
Elements
Sulphur
Number of Protons
16 Neutrons
16 Electrons
16 Boiling point 444 Freezing
point 112 State at room
temperature solid
Sulphur is found in meteorites, volcanoes, hot
springs, and as galena, gypsum, Epsom salts, and
barite. It is recovered commercially from "salt
domes" along the Gulf Coast of the USA. Jupiter's
moon Io owes its colours to various forms of
sulphur. A dark area near the crater Aristarchus
on the moon may be a sulphur deposit. Sulphur is
a pale yellow, odourless, brittle solid, which is
insoluble in water. Sulphur is essential to life.
It is a minor constituent of fats, body fluids,
and skeletal minerals.
20
Elements
Silver
Number of Protons
47 Neutrons
61 Electrons
47 Boiling point 2212 Freezing
point 961 State at room
temperature solid
Brief description Silver is somewhat rare and
expensive, although not as expensive as gold.
Pure silver has a brilliant white metallic
lustre. It is a little harder than gold and is
very ductile and malleable. Pure silver has the
highest electrical and thermal conductivity of
all metals, and possesses the lowest contact
resistance.
21
Elements
Gold
Number of Protons
79 Neutrons
118 Electrons
79 Boiling point 2807
Freezing point 1064 State at
room temperature solid
Brief description gold is usually alloyed in
jewellery to give it more strength, and the term
carat describes the amount of gold present (24
carats is pure gold). It is estimated that all
the gold in the world, so far refined, could be
placed in a single cube 60 ft. on a side. It is
metallic, with a yellow colour when in a mass,
but when finely divided it may be black, ruby, or
purple.
22
Elements
Uranium
Number of Protons
92 Neutrons 141-146
Electrons 92 Boiling
point 3818 Freezing
point 1132 State at room
temperature solid
Brief description uranium is of great interest
because of its application to nuclear power and
nuclear weapons. Uranium contamination is an
emotive environmental problem. It is not
particularly rare and is more common than
beryllium or tungsten for instance