Prelims - The Atom and Electron Configuration

Isomers

Isomers

these are nuclides with the same number of protons and neutrons having different energy states and spins; These are nuclides in a metastable state caused by the excitation of one or more of its nucleons (protons or neutrons)

Metastable state

is usually referred to isomers with half-lives of 10-9 seconds or longer

Isotones

these are nuclides having the same number of neutron number (N) but different in number of proton (Z)

Isobars

these are nuclides of different chemical elements that have the same number of nucleons

atomic number (Z), mass number (A)

isobars differ in _____ but have the same _____

Isotopes

these are nuclides of the same element having the same atomic number (Z) but different mass numbers (A)

Nuclide

it is an atomic species with a definite number of protons and neutrons arranged in a definite order in the nucleus

Truman P. Kohman (1947)

The word nuclide was proposed by who and when?

Radionuclides

these are nuclides that are unstable and thus decay by emission of particles or electromagnetic radiations or by spontaneous fission

Ionization

the ejection of an electron from an atom, creating an ion pair

Cation

positively charged ion

Anion

negatively charged ion

ELECTRON BINDING ENERGY

It is the strength of an attachment of an electron to the nucleus of an atom

Valence electrons

the electrons found in the outermost shell of an atom

Pauli exclusion principle

Each orbitals can only contain 2 electrons

Orbitals

these are complex-shaped high probability regions of space around the nucleus occupied by electron shells

Sub-shell

Introduced by Schrödinger

Shell number n

the principal quantum number

ELECTRON CONFIGURATION

The exact location of an electron orbiting the nucleus is impossible to determine at a given point in time

GRAVITATIONAL FORCE

The pull between two objects directly related to their masses and inversely related to the distance between them (Newton)

GRAVITATIONAL FORCE

This force is most powerful for massive and slow objects (Earth, stars), but has little effect at atomic level

Graviton

Gravitation force is thought to use a particle called what?

WEAK NUCLEAR FORCE

This is the force that is responsible for the decay of radioactive atoms and the emission of particles from the nucleus; It also causes the nuclear fusion in the sun and stars

W and Z bosons

Weak nuclear force uses what bosons?

ELECTROMAGNETIC FORCE

Acts between charged particles and is the combination of all electrical and magnetic forces; It is the force that holds the electrons in orbit around the positively charged nucleus

Photons

electromagnetic force uses what?

STRONG NUCLEAR FORCE

The force that hold nucleons together; Strongest of all forces but acts only at short range (size of nucleus)

pions and gluons

strong nuclear force uses what?

Force

a push or pull upon an object resulting from the object’s interaction with another object

Neutrinos

these are sub-atomic particles much like electrons with no electric charge, very small and virtually no mass

Negatron

negatively charged; used to negate positron

Positron

The anti-matter of electron; It is a very light particle with the same mass as the electron but with opposite charge (+1)

Carl Anderson (1933)

Who discovered positron and when?

Anti-matter

“completely the opposite”; For every particle, there is an what?

Gauge bosons

these are the glue that holds particles of the atom together which holds a huge amount of energy

Higgs boson

it is a scalar boson; Produced by the quantum excitation of the Higgs field; Known to be responsible for the black hole

2013

When was Higgs Boson discovered?

Electron

both fundamental and elementary

Lepton

Electron is considered as a what?

Nucleus

It is at the center of the atom and contains the protons and neutrons

Nucleons

Protons and neutrons are collectively known as _____

Ernest Rutherford (1911)

Nucleus was discovered by who and when?

NEUTRON

Large and heavy particle; slightly heavier than proton; no electrical charge

Sir James Chadwick (193)

Neutron was discovered by who and when?

PROTON

Much larger and heavier than electrons; have a positive charge

Ernest Rutherford (late 1919)

The discovery of proton was credited to _____

LINAC (Linear Accelerator)

used in radiation therapy; A device that accelerates electrons to velocities near the speed of light; Located underground as it carries tremendous amount of energy

Electron

Tiny, very light particles; million times smaller than protons and neutrons; Have a negative electrical charge

Joseph John Thomson (1897)

Electron was discovered by who and when?

Atom

the smallest part of an element that has all the properties of that element

Quarks

smaller particles of protons and neutrons

Joseph John Thomson (1897)

Electron was discovered by who and when?