Match List I and List II and select the correct answer by using the codes given below
List I                     List II
A. Glass           1. Phosphorus
B. Cement       2. Clay
C. Matches      3. Silica
D. Ink               4. Carbon blank
                          5. Cellulose

Stars are massive source of energy. The source of energy in all stars including the sun is
(a) unknown
(b) fusion of hydrogen nuclei into helium nucleus
(c) fission of bigger nuclei into smaller ones
(d) stored energy in the atmosphere

Chlorination is a process used for water purification. The disinfecting action of chlorine is mainly due to

Match List I and List II and select the correct answer by using the codes given below.
List I                                   List II
A. Antipyretics        1. Cure allergies
B. Analgesics           2. calm the nerves
C. Tranquilizers       3. relieve pain
D. Antihistamines   4. lower body temperature

Atomic carbon is a very short-lived species and, therefore, carbon is stabilized in various multi-atomic structures with different molecular configurations called allotropes. The three relatively well-known allotropes of carbon are amorphous carbon, graphite, and diamond. Diamond is harder than graphite because of

An atomic orbital is a mathematical function that describes the wave-like behavior of either one electron or a pair of electrons in an atom. In an atom, the order of filling up of the orbitals is governed by

Match List I and List II and select the correct answer by using the codes given below
List I                                List II
A. Melamine          1. electric fittings
B. Teflon                 2. Cups and crockery
C. Bakelite              3. Raincoats
D. PVC                     4. Non-stick utensils

Explosions and the resulting fires often kill or trap workers, block avenues of escape, and rapidly generate asphyxiating gases, threatening every worker underground. Explosions in underground mines and surface processing facilities are caused by accumulations of flammable gas and/or combustible dust mixed with air in the presence of an ignition source.  Most of the explosions in mines occur due to the mixing of

Graphite is known for its use in pencils, where it is commonly called lead. Graphite occurs in metamorphic rocks as a result of the reduction of sedimentary compounds during metamorphism. Consider the following statements regarding graphite
(a) It is an allotrope of carbon.
(b) It is good conductor of heat and electricity.
(c) It can be artificially produced.
Of these statements

Assertion (A): Coal-based thermal power stations contribute to acid-rain.
Reason (R): Oxides of carbon are emitted when coal bums. Codes