8. Definition
the structure of an atom, theoretically consisting of a positively charged nucleus
surrounded and neutralized by negatively charged electrons revolving in orbits at
varying distances from the nucleus, the constitution of the nucleus and the
arrangement of the electrons differing with various chemical elements.
In Physics.
Atomic Structure
AtomIn Physics.
the smallest component / object of an element having the chemical properties of the
element, consisting of a nucleus containing combinations of neutrons and protons and
one or more electrons bound to the nucleus by electrical attraction; the number of
protons determines the identity of the element.
OR
An atom is the defining structure of an element, which cannot be broken by any
chemical means. A typical atom consists of a nucleus of protons and neutrons with
electrons orbiting this nucleus.
11. Electron
Electron (symbol: e−) is a subatomic particle with a negative elementary electric charge It
is generally thought to be an elementary particle electron because it has no known
components or substructure. An electron has a mass that is approximately 1/1836 that of
the proton
12. Proton
The proton is a subatomic particle with the symbol p or p+ and a positive electric charge of
1 elementary charge. One or more protons are present in the nucleus of each atom. The
number of protons in each atom is its atomic number. Protons and neutrons are both
nucleons
Hydrogen
The quark structure of the proton.
Proton
13. Neutron
The neutron is a subatomic hadrons particle which has the symbol n or n0, no net
electric charge and a mass slightly larger than that of a proton. With the exception
of hydrogen-1, nuclei of atoms consist of protons and neutrons, which are
therefore collectively referred to as nucleons.
Cold neutron source providing neutrons at
about the temperature of liquid hydrogen
Neutron
14. Electrons, which belong to the first generation of the lepton particle family,[10]
participate in gravitational, electromagnetic and weak interactions.[11] Like all matter, they
have quantum mechanical properties of both particles and waves, so they can collide with
other particles and can be diffracted like light. However, experiments with electrons best
demonstrate this duality because electrons have a tiny mass. Being fermions, no two
electrons can occupy the same quantum state, in accordance with the Pauli exclusion
principle.[10]
15. The proton is a subatomic particle with the symbol p or p+ and a positive electric charge of
1 elementary charge. One or more protons are present in the nucleus of each atom. The
number of protons in each atom is its atomic number. The name proton was given to the
hydrogen nucleus by Ernest Rutherford in 1920, because in previous years he had
discovered that the hydrogen nucleus (known to be the lightest nucleus) could be
extracted from the nuclei of nitrogen by collision, and was thus a candidate to be a
fundamental particle and building block of nitrogen, and all other heavier atomic nuclei.
In the modern Standard Model of particle physics, the proton is a hadron, composed of
quarks. Prior to that model becoming a consensus in the physics community, the proton
was considered a fundamental particle. In the modern view, a proton is composed of three
valence quarks: two up quarks and one down quark. The rest masses of the quarks are
thought to contribute only about 1% of the proton's mass. The remainder of the proton
mass is due to the kinetic energy of the quarks and to the energy of the gluon fields that
bind the quarks together.
Proton
16. The neutron is a subatomic hadron particle which has the symbol n or n0, no net electric
charge and a mass slightly larger than that of a proton. With the exception of hydrogen-1,
nuclei of atoms consist of protons and neutrons, which are therefore collectively referred
to as nucleons. The number of protons in a nucleus is the atomic number and defines the
type of element the atom forms. Neutrons are necessary within an atomic nucleus as they
bind with protons via the nuclear force; protons are unable to bind with each other (see
diproton) because their mutual electromagnetic repulsion is stronger than the attraction of
the nuclear force.[4] The number of neutrons is the neutron number and determines the
isotope of an element. For example, the abundant carbon-12 isotope has 6 protons and 6
neutrons, while the very rare radioactive carbon-14 isotope has 6 protons and 8 neutrons.
Neutron
