Question 1 What is the atomic number and mass number of carbon?
Question 2 Give few properties of Carbon compounds ?
Question 3 What is the electronic configuration of carbon?
Question 4 Why carbon cannot lose 4 electrons?
Question 5 Why carbon cannot gain 4 electrons?
Question 6 Why is carbon atom tetravalent in nature?
Question 7 Why carbon forms covalent compounds?
Question 8 What is covalent bond ?
Carbon
Carbon has immense significance to us in both its elemental form and in the combined form.
The earth’s crust has only 0.02% carbon in the form of minerals (like carbonates, hydrogen carbonates, coal and petroleum) and the atmosphere has 0.03% of carbon dioxide. In spite of this small amount of carbon available in nature, the importance of carbon seems to be immense.
Carbon has atomic number 6 and atomic mass 12.
Its electronic configuration is 2,4 .Since it has 4 valence electrons, it is tetravalent in nature.
Bonding in Carbon Compounds
Most carbon compounds are poor conductors of electricity.The boiling and melting points of the carbon compounds is lower as compared to ionic compounds.The forces of attraction between the molecules are not very strong. Since these compounds are largely non-conductors of electricity, we can conclude that the bonding in these compounds does not give rise to any ions.
The reactivity of elements is explained as their tendency to attain a completely filled outer shell, that is, attain noble gas configuration. Elements forming ionic compounds achieve this by either gaining or losing electrons from the outermost shell.
Electronic configuration of carbon is 2,4.In the case of carbon, it has four electrons in its outermost shell and needs to gain or lose four electrons to attain noble gas configuration.
1) It could not be gain 4 electrons from some other atom and become C4-
In this case the energy required is expected to be very high in order to overcome the repulsion in the electrons already present in the carbon atom and the electrons which it has to accept.
It would be difficult for the nucleus with 6 electrons to hold on 10 electrons i.e. 4 extra electrons.
2) It could not be lose 4 electrons present in the valence shell to some atom and become C4+
Since 4 electrons are to be lost, the energy needed for the purpose is going to be very high and not easily available.
Carbon overcomes this problem by sharing its valence electrons with other atoms of carbon or with atoms of other elements. Not just carbon, but many other elements form molecules by sharing electrons in this manner. The shared electrons ‘belong’ to the outermost shells of both the atoms and lead to both atoms attaining the noble gas configuration.
Therefore carbon atom shares its valence electrons with other atoms of carbon or with atoms of some element forming a Covalent Bond.
Priya says
Very very useful.
Patiently done.
Thanks a ton for the notes.