Periodic table

The Periodic table list the known elements according to patterns. The elements were originally arranged according to increasing atomic weight and in groups of similar chemical and physical properties. It was later found that arranging the elements according to the number of protons in the nucleus or Atomic Number was more correct.

Beryllium

Beryllium is an alkali earth metal which is found in group II of the Periodic table.

Beryllium has a relative low density and is resistant to corrosion. It is used in high strength alloys in the the manufacture of statellites, rockets and jets.

Beryllium is found in the mineral beryl which is found in gemstones such as emeralds. The chemical formula of beryl is Be₃Al₂(SiO₃)₆

Bixbit or red beryl is a rare gemstone which contains the lement Beryllium and is found in Utah.

Chemical name:

Beryllium

Chemical symbol:

Atomic Number:

Electron configuration:

2.2

Atomic weight:

9.012 amu

Melting point:

1278 ºC

Boiling point:

2469 ºC

Physical state:

Solid

Density:

1.85 g/cm3

Helium

Helium is a colorless unreactive gas that is less dense that air. It belongs to the Noble gases which is the last group on the far right of the Periodic table.

All of the Noble gases are chemically unreactive because they contain a complete number of electrons in the outer shell.

Helium gas if often used in party balloons as it is lighter than air.

Helium is also found in the sun and the stars where it is formed through a series of nuclear fusion reactions involving hydrogen.

Most of the helium used today comes from natural gas deposits in the US where it has been trapped below the surface of the Earth.

Chemical name:

Helium

Chemical symbol:

Atomic Number:

Electron configuration:

Atomic weight:

4.0026 amu

Melting point:

-272 ºC

Boiling point:

-269 ºC

Physical state:

Gas

Hydrogen

Hydrogen is a colorless gas that is less dense than air and is highly flammable.

The "pop test" is used to identify hydrogen gas in the school laboratory. A test tube mixture of hydrogen and air will pop when ignited producing water as a by-product. The chemical reaction is

Hydrogen + oxygen ==> Water + Energy

2H₂+ O₂ ==> 2H₂O + Energy

The Hindenburg was a German airship that was filled with hydrogen gas. On landing in the USA in 1937 after a transalantic flight the passenger airship caught fire. Thirty six people died.

The airship did not contain a mixture of hydrogen and oxygen which would of caused and immediate explosion. It burnt as the hydrogen in the airship combined with the oxygen from the atmosphere.

Today, airships use helium gas which is non flammable.

Hydrogen exists as a diatomic molecule and has the formula H₂

Chemical name:

Hydrogen

Chemical symbol:

Atomic Number:

Electron configuration:

Atomic weight:

1.008 amu

Melting point:

-259 ºC

Boiling point:

-253 ºC

Physical state:

Gas

Lithium

Lithium belongs to Group 1 of the periodic table which is commonly called the Alkali metals.

The element lithium is less dense than water, soft being able to be cut with a knife and very reactive. It is stored in liquid paraffin oil to prevent it from reacting.

When a small piece of lithium is placed in a beaker of water it reacts with the water producing hydrogen gas and lithium hydroxide. The hydrogen can be ignited with a match and lithium ions produce a deep red or crimson flame color.

The flame color for lithium salts is also red-crimson in color.

Lithium is extensively used in batteries. Lithium has a high electrically potential and produces a relatively high voltage compared to other batteries. Lithium metal has a low density which means that lithium batteries are relatively light. These properties make lithium batteries ideal for use in portable appliances such as laptop computers and digital and video cameras.

Chemical name:

Lithium

Chemical symbol:

Atomic Number:

Electron configuration:

2.1

Atomic weight:

6.941 amu

Melting point:

180 ºC

Boiling point:

1342 ºC

Physical state:

Solid

Density:

0.53 g/cm3

Periodic table quiz

Do you know the basic structure of the Periodic table? What is an alkali metal? What elements are man made? What is a transition metal? Is chlorine a noble gas or a halogen? If you think you are ready then take the quiz.

Ten questions are randomly selected from the database