[can be beaten into sheets], ductile [pulled into wires]
and conductors of heat
and electricity, sonorous [produce ringing sounds when
sodium, potassium [alkali metals] are soft and can be
is liquid at
is a non metal but lustrous.
exits as different
allotropes like diamond [hardest substance, sharpening
tungsten filaments for light bulbs, cutting, grinding],
and graphite [conductor
of electricity, lubricant in machines where oil can’t be
used due to high
Facts of Metals
metals are basic and non metals are acidic.
Sodium is very reactive with oxygen
and hence stored in kerosene. Phosphorous reacts with
oxygen so kept in water.
react with acids
to produce hydrogen gas. Non metals don’t react.
reactive metals can
replace less reactive metals in reactions.
of 98 naturally occurring
elements, 20 are non metals. Most are metals. Bromine is
non metal, which is
liquid at room temperature. Metalloids have property of
both metals and non
metals. e.g.: boron, silicon, and germanium.
is a pure form of
carbon, used in manufacture of steel.
tar is starting
material for synthetic fibers, drugs, naphthalene balls
are made from coal tar.
Properties of Match-stick:
trisulphide and potassium chlorate. The rubbing surface
has powdered glass and
red phosphorous. On striking the surface, red
phosphorous get converted to
white phosphorous which reacts with potassium chlorate
to create enough heat to
ignite the antimony trisulphide.
dioxide as an extinguisher:
is a good fire
extinguisher if petrol or oil is burning. Even
electrical fires are
extinguished by using CO2 as it cuts off oxygen supply
to fire by making a
protective blanket as it’s heavier than O2.
amount of heat
energy produced on complete combustion of 1 kg of a fuel
is called its
calorific value. The calorific value of a fuel is
expressed in a unit called
kilo-Joules per kg (kJ/kg).
paper cup filled with
water doesn’t burn as heat is transferred to the water
and it doesn’t reach its ignition temperature.
Glycol [antifreeze] reduces freezing point of
water to -17.2C.
of chemical compositions:
can neither be
created nor destroyed in a chemical reaction.
the elements are always present in definite proportion
atomic mass unit was
equal to exactly one twelfth the weight of one atom of
particles, positively charged are cat ions and
negatively charged are anions.
number of particles
present in 1 mole of any substance is fixed as
6.022*10^23. 1 mole of a
substance is its relative atomic or molecular mass in
1 mole of carbon
atoms = 12 g of carbon atoms.
electrons were discovered by J.J.Thomson by the
cathode ray experiment and
protons were discovered by Goldstein. Chadwick
number is the
number of protons in an atom. Mass number is the sum of
protons and neutrons.
atomic number [due to same number of protons but
different number of neutrons]
but different mass numbers. e.g.: isotopes of hydrogen
are protium, deuterium
and tritium. Chemical properties of isotopes are same
[as they depend on
electronic structure] but their physical properties are
isotope of cobalt is used to treat cancer. Isotope of
iodine is used to treat
different elements with same mass number but different
number of neutrons but different number of protons [and
discovered radioactivity. In this an unstable nucleus
ά – Decay:
helium nucleus is emitted.
Heavy, slow, least penetrating, easily blocked, positive
electrons or positrons are
emitted. Less Heavy, fast, more penetrating [100 times
more than alpha], tough
to block, negatively / positively [positron] charged.
energy photons are
emitted. Lightest, fastest, highly penetrating [1000
times more than alpha],
toughest to block, no charge.
is the most
abundant element in the universe [70% of total mass of
the universe]. Oxygen is
the most abundant element [up to 47%] on earth.
mixture of CO and H2 is
called water gas or synthetic gas. It’s used in
the synthesis of hydrocarbons
of vegetable oils using nickel as catalyst gives
regia is mixture
of hydrochloric and nitric acid in ratio of 3:1 it can
dissolve even gold and platinum.
is oxygen and nitrous
oxide. Carbogen is 95% oxygen and 5% CO2, it
stimulates natural breathing.
of candle flame: Outer zone [blue] – hottest,
middle zone [yellow] –less
hot, inner zone [black] – least hot.
In limestone caves, stalactites are seen hanging from the roofs and stalagmites are seen at the bottom of the cave.
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