can anyone define following terms of chemistry with examples????

Question

the terms are:

1. isomers
2. isobars
3. isotopes
4. allotropes

Answer 1

isomers chemistry
http://en.wikipedia.org/wiki/Isomers
nuclear
http://en.wikipedia.org/wiki/Nuclear_isomer

In nuclear physics, two nuclides with the same mass number are called isobars. For example, boron-12 and carbon-12 are isobars.

isotope
http://en.wikipedia.org/wiki/Isotope

Isotone - one of multiple nuclides with equal numbers of neutrons

allotrope
http://en.wikipedia.org/wiki/Allotrope

Answer 2

Allotropy (Gr. allos, other, and tropos, manner) is a behavior exhibited by certain chemical elements: these elements can exist in two or more different forms, known as allotropes of that element. In each different allotrope, the element's atoms are bonded together in a different manner.

Diamond and Graphite are allotopes of Carbon.

http://en.wikipedia.org/wiki/Allotropes


Isomers are molecules with the same chemical formula and often with the same kinds of chemical bonds between atoms, but in which the atoms are arranged differently (analogous to a chemical anagram). Many isomers share similar if not identical properties in most chemical contexts. This should not be confused with a nuclear isomer, which involves a nucleus at different states of excitement.

C4H10 is a good example of this. Butane [CH3-CH2-CH2-CH3] (daylight SMILES CCCC) and iso-propane[CH3-CH(-CH3)-CH3] (daylight SMILES CC(C)C).

http://en.wikipedia.org/wiki/Isomer

Isobar,
In meteorology, thermodynamics, and similar science (and engineering), an isobar is a contour line of equal or constant pressure on a graph, plot, or map.

In nuclear physics, two nuclides with the same mass number are called isobars. For example, boron-12 and carbon-12 are isobars.

http://en.wikipedia.org/wiki/Isobar

Isotopes are any of the several different forms of an element each having different atomic mass (mass number). Isotopes of an element have nuclei with the same number of protons (the same atomic number) but different numbers of neutrons. Therefore, isotopes have different mass numbers, which give the total number of nucleons—the number of protons plus neutrons.

http://en.wikipedia.org/wiki/Isotope

Answer 3

a) Isomer: chemical with the same empirical formulas, but different chemical structures; examples: 1,2-dichloroethane and 1,1-dichloroethane

b) Isobar: a line describing areas of equal barometric pressure (similar to a contour line on a topographic map). See your local weather channel for examples

c) Isotope: Atoms of the same element with differeing numbers of neutrons in the nucleus; examples Carbon-12 (6 protons, 6 neutrons), Carbon-13 (6 protons, 7 neutrons) and Carbon-14 (6 protons, 8 neutrons)

d) Allotropes: Different forms of the same element, such as for Carbon -- diamond, graphite, charcoal, and carbon black. All are entirely carbon, but have widely differing physical characteristics because of their physical structures.

Answer 4

Isomers have the same formula but are different compounds
e.g. ethoxyethane and butane

Isobars are areas with identical pressures

Isotopes are differing atomic forms of the same element but with different numbers of neutrons
e.g. nitrogen-14 and nitrogen-15

Allotropes of elements are composed of the same types of atom, but are distinguished by the arrangement of the composite atoms and their properties.
e.g. graphite and diamond