Chemistry of Life » The Periodic Table

Period I Elements:


Period II Elements:


Period III Elements:


Period IV Elements:


Period V Elements:


Period VI Elements:


Period VII Elements:


Elements 57-70 (denoted by La-Lu in the table) are called the Lanthanides or Rare Earths Elements 89-102 (denoted by Ac-Lr in the table) are called the actinides. The elements of these two groups are shown in shown in the supplementary table below.





All chemical elements are denoted by their symbols – thus H=Hydrogen, Cl=Chlorine, Na=Sodium, etc...
Colour Code:
(Green) = abundant in living organisms,
(Yellow) = trace amounts in living organisms and
(Red) = only found in radioactive forms (isotopes).

The Periodic Table is given above purely for reference but it is much easier when we consider that only TWELVE of the elements seem to be be abundant in living organisms. They are marked in GREEN. A few others such as (cobalt), copper(Cu), zinc(Zn), manganese(Mn), chromium(Cr), vanadium(V), selenium(Se), boron (B), fluorine(F), iodine(I), moybdenum(Mb) and tungsten(W) occur in trace amounts in living organisms and may be essential in tiny quantities to some or even all organisms. They are marked in YELLOW.

Ray Goodwin

Somewhere there are mountains
Glistening in the snow
Somewhere there are mountains
That we shall never know

Somewhere there are rivers
Flowing fast and free
Somewhere there are rivers
That we can never see

Somewhere there are oceans
And sun drenched island sands
Forests full of creatures
In vastly distant lands

Somewhere there’s a planet
Beneath an alien star
The people watch our tiny sun
And wonder where we are

One day perhaps we’ll find them
Across the void of space
Perhaps through ways as yet unknown
We’ll meet them face to face

The author of this web site Ray Goodwin holds B.Sc. Degrees from London University in Chemistry, Geology and Physiology and an M.Sc. in Biochemistry. He has spent most of his professional life teaching in Colleges of Technology. On his retirement he has entered the fields of astronomy, astrochemistry, astrobiology and space sciences. He has spent a great deal of his retirement in visiting amateur astronomy societies and in attending European Space Agency Symposia in ESTEC in the Netherlands and other scientific conferences in England and Sweden. He regularly attends the yearly European Astrofest in South Kensington London and other meetings in the UK. He has written scientific articles and given a number of lectures on diverse scientific subjects.

Readers of this web site are invited to e-mail the author ( and discuss their opinions of the topics dealt with and suggest any changes which they think may be helpful.

Life in the Cosmos Website
Version 01.00 - April 20, 2015.