Friday, 17 June 2016
Tuesday, 31 May 2016
Definitions
Definitions
Matter is anything that occupies space and has mass
and made up of tiny particles.
ATOM is the smallest particle of a substance or
the fundamental unit of the matter.
Atom may or
may not exist independently.
An atom is
composed of sub-atomic particles called proton,
electrons and Neutrons.
MOLECULE: A molecule is formed when two or more atoms
of same or different kind combine chemically.
ELEMENT: An element
is a pure substance made up of identical atoms.
COMPOUND: Two or more atoms of different kind combine
chemically in a fixed proportion to form a compound.
ATOMICITY: The number of atoms present in a molecule of
an element is called its atomicity.
ATOMIC NUMBER (Z): The number of protons present in the nucleus
of an atom of an element is
called
its Atomic number.
MASS NUMBER (A): The total number of protons and neutrons
present in the nucleus of an atom of
an element.
ELECTRONIC CONFIGURATION: The distribution of electrons in the shells
(or) orbits in atom is
called
electronic configuration.
STABLE ELECTRONIC CONFIGURATION:
If
an element has completely filled valence shell or 8 valence electrons then it
is said to have stable electronic configuration.
OCTET CONFIGURATION: If an element has 8 valence electrons it is
called Octet configuration.
VALENCY:
ELECTRO-VALENCY: The number of electrons that an atom of an
element loses or gains to attain stability is called the electro-valency of
that element.
COVALENCY: The number of electron pairs which an atom
of an element shares with atoms of the same or different kind to attain
stability.
ION: An ion
is an atom or a group of atoms carrying a charge (positive or negative).
Positively
charged ions are termed as Cations and
those which are negatively charged as Anions.
CHEMICAL BOND: The force of attraction by which two or more
atoms of same or different kind are held together is a chemical bond.
ELECTROVALENT BOND: The strong electrostatic force of attraction
that holds two oppositely charged ions together which are formed as a result of
transfer of electron/s.
COVALENT BOND: A covalent bond is formed due to the mutual
sharing of electron pairs between two non-metallic atoms.
CO-ORDINATE COVALENT BOND: It is a covalent bond in which both the
electrons in the bond coming from the same atom.
ATOMIC RADIUS: The distance between the centre of the
nucleus and the valence shell of an atom.
ELECTRONEGATIVITY: The tendency of an element to attract the
bond pair of electrons towards itself .
ELECTRON AFFINITY: The amount of energy released when an atom
accepts an electron to form an anion.
IONISATION POTENTIAL: The minimum amount of energy required to
remove an electron from the valence shell of an atom in gaseous state.
Subscribe to:
Posts (Atom)