What are the atom and the nucleus?
Atom and nucleus are the very important terms in physics. let’s talk about these.
Atom: An atom is the smallest constituent of any matter which has many properties exits in nature.
An atom is presented in many phases either it is solid-liquid gas or plasma.
Since an atom is the smallest particle in nature it cannot be seen by naked eyes.
An atom is typically a size of around 100 picometers.
John Dalton first used the idea of atoms in the 1800s.
Nucleus: A nucleus is made from proton and neutron.
Proton is positively charged particles and neutrons are neutrally charged particles and made of very tiny particles called quarks.
The nucleus is very small in size as compared to the size of an atom.
The size of the nucleus is about 1.75fm( in case of hydrogen) and the radius of an atom is ranging from 0.05 to 0.25 nanometers.
The nucleus is bounded by a very strong force which is stronger than the electrostatic force of attraction.
As a result, the proton which is positively charged particles repels each other.
As we know that protons and neutrons are fermions and obey the Pauli Exclusion Principle are all elementary particles.
Different terms in atom and nucleus.
Atomic number: Atoms of the same element have the same numbers of the proton are called the atomic number.
The atomic number is presented by a symbol of the alphabet “Z”.
For example, Hydrogen has atomic no. 1(Z=1).
The total number of protons and neutrons in an atom is called nucleon or mass number.
For example, hydrogen has atomic no. 1 it has 1 proton and 1 neutron, it has a mass number of 2.
The mass of an atom is called atomic mass in any element.
It’s a formula to measure the mass in gram is
1u=Molar mass constant(Mu) / Avogadro constant(NA) =1 g/mol /Avogadro number.
The atomic mass unit is (amu) which is a unified atomic mass unit and symbol ( u ).
When the unified atomic mass unit becomes dimensional values then called relative isotopic mass.
The relation between the atom and the nucleus.
The nucleus is present at the center of atoms in elements.
In nucleus proton and neutrons are presents, and inside nucleus.
In the atom, electrons are revolving around the nucleus but not inside the nucleus like protons and neutrons.
The electron is negatively charged particles.