distinguish between atomic number and mass number of an element
What is the difference between atomic number and mass number of an element?
Answer:
Atomic number and mass number are two fundamental concepts used to describe an element in chemistry. While they both provide important information about an element, they represent different characteristics.
-
Atomic Number:
The atomic number of an element represents the number of protons in the nucleus of an atom. It is a unique identifier for each element and determines its position in the periodic table. The atomic number is denoted by the symbol ‘Z’ and it defines the element’s chemical properties. For example, all hydrogen atoms have an atomic number of 1, while all oxygen atoms have an atomic number of 8. -
Mass Number:
The mass number of an element represents the sum of protons and neutrons in the nucleus of an atom. It is denoted by the symbol ‘A’. Since neutrons have a mass similar to that of protons, the mass number is used to calculate the approximate atomic mass of an element. In other words, it gives the total number of nucleons (protons + neutrons) present in an atom of an element. For example, helium has a mass number of 4, which means it has 2 protons and 2 neutrons.
In summary, the atomic number identifies the element and determines its chemical properties, while the mass number represents the sum of protons and neutrons and is used to calculate the approximate atomic mass of an element.