The New Childrens Encyclopedia

SCIENCE

O

Also known as
biotin or vitamin H
O

First isolated
in 1941 by Vincent
Du Vigneaud

Vitamin B 7 is one of

eight molecules that make up the

vitamin B complex. This essential

vitamin is vital for cell growth.

Sources include liver, brewer’s yeast,

and dairy products.

Vitamin B
7
C 10 H 16 N 2 O 3 S

Vitamin D

C 28 H 44 O

Diamond

C

O

Also known

as ethanol

O

Formed by the action of of

yeast on natural sugars.

The word alcohol is the common

name for ethanol, which is the type

of alcohol found in beer, wine, and

spirits. In concentrated form it kills

germs. Doctors and nurses use it to

clean the skin before an injection.

Alcohol

C 2 H 6 O

Glucose
C 6 H 12 O 6

O

Also known

as cholecalciferol

O

First isolated

in 1922 by Edward

Mellanby

Vitamin D is essential for

building strong bones. This molecule

is made in the body when the skin is

exposed to sunlight. Other sources

include cereals and fatty fish.

O

Hardest known

substance in nature

O

Highly prized as a

gemstone for jewellery

Diamond is a rare form of carbon in

which each carbon atom bonds with

four other carbon atoms to form

a tightly packed crystal structure.

Diamonds are very hard so they

are used to make the tips of drills.

O

Also known
as dextrose
O

First isolated
from raisins in 1747 by
Andreas Margaff

Plants make this simple sugar using

the energy in sunlight. Animals eat

these plants and other animals and

then use the glucose in them as a

source of energy to stay alive.

Water

H 2 O

O

Covers around 70 percent

of Earth’s surface

O

Essential for life

Without water, life on

Earth could not survive. This simple

molecule makes up around 70 percent

of the human body. Water is the only

molecule that exists on Earth in three

different forms—as a solid (ice), a gas

(water vapor), and liquid (water).

MOLECULES Atoms stick together to form bigger

particles called molecules. The force that holds them

together is called a chemical bond. Atoms form chemical

bonds by donating or sharing electrons with other atoms.

 EACH DROP OF WATER

below is made up of three atoms—

one oxygen atom (light blue) and

two smaller hydrogen atoms (white).