*GENERAL SCIENCE

1Q. what is an alloy ?
Ans : It is Homogenous Mixture
of two more metals which looks
like a single metal .
most commonly
alloy Stainless steel
2Q: Difference between
annealing ,hardening and
tempring ?
Ans : > Anealing is making a
metal soft by heating to very
high temprature and then
cooling slowly
> Hardening is making
metal brittle by heating to very
high temp. and cooling
suddenly by plunging into
cold water
> Tempring is making a
metal elastic by heating to
moderately high temp and
cooling slowly .
3Q: Why activated charcoal is
used in gas mask especially in
coal mines ?
Ans : Activated charcoal
possesses the property of
absorbing the much more
gaseseous substances than
ordinary charcoal and
therefore used in gas mask to
trap poisonous gases and
prevent from bieng
inhaled .
4Q: what is difference
between hard water,soft water
and heavy water ?
Ans : Hard water Does not
produce lather with soap. Hard
water contains soluble salts of
calcium and
magnesium which form
insoluble precipitate with soap
Soft water readily yield
plenty of lather with soap
Heavy water is readily
useful in nuclear reactors It is
usually obtained from ordinary
water by
electrolysis
5Q: Slaked Lime vs Quick
Lime ?
Ans : Quicklime (CaO) is a
basic oxide of calcium, which
on treatment with water form
Calcium hydroxide
(Slaked Lime )with the
evolution of large amount of
heat .
QuickLime is used for
metallurgical purpose ,whereas
slaked lime is used to make
mortar, plasters
and cement.
6Q : Coal vs Coke ?
Ans : Coal is carbonaceous
mineral formed by the
decomposition of vegetable
matter in the interior of earth .
Coke is obtained by the
destructive distillation of
coal ,it has advantage over coal
as afuel as it burns
without smoke
7Q: Difference between Lignite
and anthracite type of coal ?
Ans : In the formation of coal
under the earth's surface, the
first step is the conversion of
vegetable matter
into peat by decompostition at
high temperatures and
pressure .Peat then converted
into brown coal called
Lignite,which still has some
vegetable matter and leaves in
it .This is soft ,lustrous and
burn with a flame The
last stage is slow conversion of
Lignite into anthracite which
contains only carbon.ithas a
brilliant lustre and is
very hard ,it does not burn
with a flame and gives intense
heat .
8Q: what is Bioterrorism ?
Ans : Bioterrorism : When
terrorist infecting themselves
with deadly germs and then
spreading the disease
through the
population.Bioterrorist could
infest themself with a
contagious disease such as
smallpox or ebola and
could go into crowd public
areas and try to spread the
disease by close contact
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