CH 3 ELEMENTS,
COMPOUNDS AND
CHEMICAL EQUATION
All living and non-living matter on the earth is
made of some basic components
WHAT IS AN ATOM
The basic building block of all matter is
atom.
Atoms are tiny, indivisible particle that
have the characteristic properties of a
substance.
The term atom is derived from a Greek
word ‘atomos’ that means indivisible.
ELEMENTS
o Antoine Laurent Lavoisier, a French chemist,
was the first to establish a useful definition of
an element.
, o Element was defined as the basic form of
matter, which cannot be broken into simpler
substances by chemical reactions.
o An element contains only one type of atoms,
which have the same properties.
o For example, a lump of sodium contains just
sodium atoms which have the same mass and
chemical properties, while pure gold consists
of just gold atoms.
o Atoms of different elements have different
masses and chemical properties.
o Currently, 188 elements are known to exist
out of which 98 are naturally occurring in the
earth’s crust.
o While some of them are prepared in
laboratories.
o Aluminum, copper, zinc, hydrogen, oxygen,
nitrogen, potassium, and sodium are some of
the elements.
o Oxygen the most abundant element in the
earth’s crust.
COMPOUNDS AND
CHEMICAL EQUATION
All living and non-living matter on the earth is
made of some basic components
WHAT IS AN ATOM
The basic building block of all matter is
atom.
Atoms are tiny, indivisible particle that
have the characteristic properties of a
substance.
The term atom is derived from a Greek
word ‘atomos’ that means indivisible.
ELEMENTS
o Antoine Laurent Lavoisier, a French chemist,
was the first to establish a useful definition of
an element.
, o Element was defined as the basic form of
matter, which cannot be broken into simpler
substances by chemical reactions.
o An element contains only one type of atoms,
which have the same properties.
o For example, a lump of sodium contains just
sodium atoms which have the same mass and
chemical properties, while pure gold consists
of just gold atoms.
o Atoms of different elements have different
masses and chemical properties.
o Currently, 188 elements are known to exist
out of which 98 are naturally occurring in the
earth’s crust.
o While some of them are prepared in
laboratories.
o Aluminum, copper, zinc, hydrogen, oxygen,
nitrogen, potassium, and sodium are some of
the elements.
o Oxygen the most abundant element in the
earth’s crust.
