Category: chemistry

what is the difference between mechanical and chemical digestion ?

Mechanical digestion :- In this type of digestion the food is broken down into simple particles in mechanical way , like chewing in mouth by teeth and churning of food in stomach by the muscular movements of the smooth muscles of stomach walls. Chemical digestion :- In this type of digestion the complex molecules of

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Explain how vacancies are introduced in an ionic solid when a cation of higher valency is added as an impurity in it.

In case of ionic solids the opposite ions balance the charge of each other. The amount of cations and anions is mostly same in case of charge. But when we add a cation with higher charge , the cation can replace the other cations in lattice and can create vacancy because to balance the charge,

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A group 14 element is to be converted into n-type semiconductor by doping it with a suitable impurity. To which group should this impurity belong ?

These type of semiconductors have excess electrons present in the lattice that are responsible for the conduction. These are formed when the group 14 elements like Silicon are doped with group 15 elements like P and As. The group 14 elements have 4 valence electrons and group 15 elements have 5 valence electrons . One

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Ionic solids , which have anionic vacancies due to metal excess defect , develop colour. Explain with the help of a suitable example.

When we add extra metal to the lattice, it provide extra electrons to the lattice and the anions of the lattice leave their lattice points . These vacant sites are occupied by the electrons. And the free electron can easily absorb energy and can jump to higher level. As these energy transitions are in visible

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Which of the following lattice has the highest packing efficiency? (i) simple cubic (ii) bodycentred (iii) hexagonal close packing.

Packing efficiency of all these kind of arrangements is given as follows. (i) Simple cubic :- Its packing efficiency is 52% . (ii) Body centred cubic :- Its packing efficiency is 68%. (iii) Hexagonal close packing:- Its packing efficiency is 74% . Conclusion :- From the above data we can conclude that hexagonal close packed

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How the atomic size changes when we move from left to right in a period in modern periodic table ?

The atomic Size is an important property that governs various behaviours of an atom or an element, like valency , electronegativity and metallic character. when we move from left to right the nuclear charge increases at every increase of atomic number. Due to increase in nuclear charge the electrons are attracted towards nucleus with more

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