Burning of a match stick is ____________ change.
slow
fast
Desirable
undesirable
Curdling of milk is an __________ reaction.
endothermic
exothermic
both A&B
none of these
Burning of coal is ____________ change.
periodic
The bacteria which is involved in curdling of milk is
Lactobacillus
Streptococci
Bacillus cereus
None of these
The curdling of milk is a
Natural change
Man made change
Both A$B
Desirable change
Change of seasons is a _________ change.
man made
natural
one of these
Sublimation is a ___________ change.
Physical
Chemical
Spontaneous
Dissolution of solid in liquid (ie sugar in water) is a __________ change.
Undesirable
Periodic change take place repeatedly after a certain _________ of time.
Fixed interval
Unfixed interval
Regular interval.
Particular time.
___________ is the process where a solid turns directly into gas without entering to the liquid liquid slate.
Sublimation
Vapourisation
Lyophilisation