INTRODUCTION TO THE WORLD OF CARBON. TARGET AUDIENCE CLASS :IX AND X AGE GROUP :13 TO 15 YEARS.

INTRODUCTION TO THE WORLD OF

CARBON

TARGET AUDIENCE

CLASS :IX AND X

AGE GROUP :13 TO 15 YEARS

KUSUM

R.P.V.V SEC-10,DWARKA

ANITA MANCHANDA

G.G.S.S.NO.-3 WEST PATEL NAGAR

LEARNING OBJECTIVES

After interacting with this software, the learner will be able to :

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Identify the allotropes of carbon

Draw the structure of carbon atom.

Distinguish the isotopes of carbon

LEARNING OBJECTIVES

explain how carbon dating is used for ascertaining the age of dead objects

After interacting with this software, the learner will be able to :

.

State what is green house effect and take steps to control the pollution.

State the causes of depletion of ozone layer

1. It is in the food you eat.

2. The clothes you wear.

3. The cosmetics you use.

4. Gasoline that fuels your car.

CARBON IS FOUND IN MANY COMPOUNDS :

In addition, carbon is a very special element because it plays a dominant role in the chemistry of life.

Atoms of the element carbon can link together in several different ways to form substances with very different properties.

In diamond, the atoms form a three-dimensional network extending throughout the whole of a crystal. Because of this structure it is the hardest substance known.

ALLOTROPES OF CARBON

DIAMOND1.

ALLOTROPES OF CARBON

Graphite is made up of layers of carbon, consisting of hexagonal rings of atoms. The layers can slide over each other easily, so that graphite can even be used as a lubricant.

2. GRAPHITE

ALLOTROPES OF CARBON

FULLERENES

In the family of substance fullerenes,the

Buckminsterfullerene consists of 60

Carbon atoms forming a globe made up

Of20 Hexagons and 12 pentagons.

Atoms are linked to form spherical or

Cylindrical surfaces

3.

ISOTOPES OF CARBON

C-12

C-13

C-14

ISOTOPES OF CARBON

C-12Carbon has three naturally occurring isotopes:

carbon-12 constitutes 98.89 of all carbon atoms and serves as the standard for the atomic mass scale;

It has 6 protons and 6 neutrons

p

n

p

p

p

n n

nnP

P

n

C-12 ATOM

p

n

p

p

p

n n

nnP

P

n

C-12 ATOM

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ISOTOPES OF CARBONC-13

carbon-13 is the only magnetic carbon isotope, which makes it very important for structural studies of compounds containing carbon

It has 6 protons and 7 neutrons

ISOTOPES OF CARBON

C-14Carbon-14 is produced by cosmic ray bombardment of nitrogen. It is radioactive with a half-life of 5,760 years. The amount of carbon-14 remaining in historical artefacts can be used to estimate their age.

It has 6 protons and 8 neutrons

The number of protons an atom contains determines what that atom is. Since it now contains six protons, it's carbon. Carbon usually has six neutrons as well, in this form it's called carbon-12 (6+6=12). The unstable, eight-neutron version, however, is carbon-14 (6+8=14).

C-12 Atom

protonsneutrons

Nucleus of Carbon atom

All radioactive atoms will eventually decay, or change, in some way. When a carbon-14 atom decays, one of its eight neutrons turns into a proton, emitting an electron (with a charge of -1) in the process. The atom is now stable. And with

seven protons and seven neutrons, it is again nitrogen-14.

See how C-14 changes to N-14 atom

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Radioactive Carbon

The carbon-14 created by cosmic radiation makes up only a fraction of the carbon in our atmosphere. But it is there, and just like carbon-12, it can be taken in by a growing plant and become a part of that plant. (As you may know, plants take in carbon dioxide, or CO2, separate the carbon from the oxygen, then release the oxygen back into the atmosphere.)

Radioactive Carbon

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The percentage of carbon-14 in all of the living things is the same as the percentage of carbon-14 in the atmosphere. At least it's the same while they're living. When a plant or animal dies, no carbon (in any form) can enter its system to become a part of it.

Radioactive Carbon

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C-14 enters our body as we breathe

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The carbon-14 within every once-living thing will someday turn back into nitrogen-14. If we knew the amount of carbon-14 a once-living thing had while it was alive and the rate at which it changed (i.e., how fast it changed) back into nitrogen, then we could figure out how long ago it lived.

Radiocarbon Dating

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Click here to see animation of Green House Effect

GREENHOUSE EFFECT

GREENHOUSE EFFECT

GREENHOUSE EFFECT

GREENHOUSE EFFECT

GREENHOUSE EFFECT

GREENHOUSE EFFECT

GREENHOUSE EFFECT

GREENHOUSE EFFECT

GREENHOUSE EFFECT

GREENHOUSE EFFECT

GREENHOUSE EFFECT

GREENHOUSE EFFECT

GREENHOUSE EFFECT

GREENHOUSE EFFECT