Question

state reasons
a) articles get coated with a reddish brown powder when left for sometime in open.
b) burning of coal is an exothermic reaction.
c) the chemical equation should be balanced.

Answer 1

A) iron articles when left in the open, react with the oxygen and moisture present in the air and turns reddish-brown due to the formation of rust.
B) burning of coal is an exothermic reaction, as on heating it produces large amount of heat energy.
C) a chemical equation must be balanced so that they follow the LAW OF CONSERVATION OF MASS.

Answer 2

hey buddy..!!

may it will help you..
and sorry if the handwriting is bad..!!