(i) Excess burning of coal adds lot of to the
atmosphere. Carbon dioxide is a greenhouse gas, which allows the solar radiations to strike the Earth’s surface but prevents the escape of long wave radiations from the Earth’s atmosphere. Thus, causing greenhouse effect.
(ii) Soil is a mixture as it consists of particles (sand, silt, clay and humus) of different types which do not get dissolved in water, but settle down in layers, depending on their size.