Mass of a Nucleus
Nucleus contains almost all of an atom’s mass, with only a minor contribution from the electron cloud. The mass of an atom is related with its atomic mass number, which is the total number of protons and neutrons in its nucleus. An isotopes of an element have same atomic number but distinct mass number. The mass number is written after the element name or as a superscript to the left of an element’s symbol. Carbon-12, or 12C, is the most common carbon isotope.
Atoms are so small in size and mass that using standard measuring units, while possible, is frequently inconvenient. On atomic scale, units of mass and energy have been defined to make measurements easier to express. The atomic mass unit is the unit of mass measurement (amu).
1 amu = 1.66 x 10-24 Grams
Atomic Nucleus
The nucleus of an atom is a small, dense, round region located in the centre of an atom. It has two subatomic particles, protons and neutrons. Protons are electrically positively charged ions having a mass of approximately one atomic mass unit (amu). Neutrons are electrically neutral.
The atomic nucleus is bonded together by the strong force (also known as nuclear force), the most powerful known fundamental force in nature. The atomic nuclei have more than 99.9% of the atomic mass and are 10,000 times smaller. In 1911, Ernest Rutherford discovered the nucleus of an atom.
Before learning about the Nucleus we first need to learn about the Structure of atoms in brief so let’s start with that.
Table of Content
- Structure of Atom
- Nucleus Discovery
- Composition of a Nucleus
- Characteristics of Nucleus
- Mass of a Nucleus
- Size of Nucleus
- Atomic Number
- Atomic Mass