So can I say the term "isotope" is used when we are talking about the atoms of the same element (in which they have same atomic no. and different mass no.), while "nuclide" is generally used to talk about the nuclear part of the atom of different elements?It's a tad complciated but I'm sure it's not beyond you.
So start with nucleons.
These are protons and neutrons - the particles of the nucleus.
Since both have a mass of very nearly one wew have an identifier, the mass number = the whole number part of the atomic mass = the number of protons + number of neutrons.
But this mass number can be achieved in different ways since it is a composite of two different (otherwise independent) numbers.
For example, take mass number = 14 this could be carbon 14 (6 protons and 8 neutrons) or nitrogen 14 (7 protons and 7 neutrons)
A nucleus where both the number of neutrons and number of protons is specified is called a specific nuclide.
Where the atomic number is specified that could refer to several different nuclei, but all of the same element, with the same chemical properties (but not physical ones)
carbon 12 has 6 protons and 6 neutrons
carbon 13 has 6 protons and 7 neutrons
carbon 14 has 6 protons and 8 neutrons
These are called isotopes of the element (of carbon in this case)
All with the same chemical properties but different physical ones.
In particular this is used to identify the chemical structure of organic molecules by replacing the normal carbon 12 with carbon 13 which has very different magnetic properties.
One more complication
nuclides with switched numbers of protons and neutrons are callled mirror nuclides.
So the number of protons of one equals the number of neutrons of the other and vice versa
But they have the same mass number..
Does this help?
Is it correct to say that "nuclide" refers to the atoms of known proton no. and neutron no., so every element has different nuclide; and if an element is having more than one nuclide, then those nuclides will be called "isotopes"?Not quite.
As topsquark said
carbon12 (mass no = 12) and carbon13 (mass no = 13) and carbon 14 (mass no = 14) are all isotopes of carbon.
but they are all different nuclides.
carbon 14 (but not carbon12 or carbon 13) has the same mass no as nitrogen 14.
But they are not isotopes of each other.
and of course they are different nuclides. (So you need a different term to name them)
If you look at the equation
Mass no = proton no. + neutron no.
You have three terms or variables.
Specifying two of them allows you to deduce the third.
Only specifying one is not enough.
When I specify carbon or nitrogen (this is Chemistry after all so I don't say the element with 6 protons etc)
I am effectively specifying one of the variables in that equation.
Tying it down to carbon 12 specifies a second one.
Is it correct to say that "nuclide" refers to the atoms of known proton no. and neutron no., so every element has different nuclide; and if an element is having more than one nuclide, then those nuclides will be called "isotopes"?
I'm rly confused with these 2 terms and my questions might be quite stupid :'( Thanks for answering my questions!!
Sorry for my poor English