01) What is an Isotope?
Isotopes are atoms of the same element that have different numbers of neutrons but the same number of protons and electrons.
2) What determines the atomic number of an element?
A number of protons in the nucleus.
Examples of Isotopes:
| Element | Isotopes |
| Hydrogen | 1H (A=1), 2H(A=2) and 3H(A=3).Protium(A=1) , deuterium(A=2) and tritium (A=3). Hydrogen is the only element whose isotopes have unique names. |
| Carbon | 12 6C (A=12, 13 6C (A=13) , 14 6C (A=14) |
| Helium | 3 2He (A=3) , 4 2He (A=4) |
| Uranium | 235 92U (A=235), and 239 92U (A=239) |
| Oxygen | 16O(A=16), 17O (A=17), and 18O(A=18). |
Standard Notation of Isotopes: Also known as AZE notation 'A' is the mass number, 'Z' is the atomic number and E is for element.
It is to indicate the mass number (A) with a superscript at the upper left of the chemical symbol and to indicate the atomic number with a subscript at the lower left.
Example: Carbon-13, 13
6C
to be continued ......
