Sure! Here's an explanation of atomic number, mass number, and isotopes:
Atomic Number: The atomic number of an element represents the number of protons found in the nucleus of an atom. It is denoted by the symbol 'Z'. The atomic number determines the identity of an element because each element has a unique number of protons. For example, hydrogen has an atomic number of 1, meaning it has one proton in its nucleus, while oxygen has an atomic number of 8, indicating it has eight protons.
Mass Number: The mass number of an atom is the sum of the protons and neutrons in the nucleus. It is denoted by the symbol 'A'. While the atomic number defines the element, the mass number represents the total number of nucleons (protons and neutrons) in the nucleus. For instance, carbon-12 has a mass number of 12 since it contains six protons and six neutrons, while carbon-14 has a mass number of 14 due to its six protons and eight neutrons.
Isotopes: Isotopes are variants of an element that have the same atomic number (same number of protons) but differ in their mass numbers (different number of neutrons). In other words, isotopes of an element have the same number of protons but varying numbers of neutrons. Since the number of protons determines the element's identity, isotopes of the same element exhibit similar chemical properties. However, due to the difference in mass numbers, isotopes may have different physical properties, such as atomic mass and nuclear stability. For example, carbon-12 and carbon-14 are isotopes of carbon, with carbon-14 being radioactive and commonly used in radiocarbon dating.
In summary, the atomic number defines the element by indicating the number of protons, the mass number represents the total number of protons and neutrons, and isotopes are variants of an element with the same atomic number but different mass numbers due to varying numbers of neutrons.