11. What is the term for polluting rain or other precipitation that is caused by the combining of oxides of sulfur and nitrogen with atmospheric moisture?
(a) Heavy rain
(b) Acid rain
(c) Death rain
(d) Sulphur rain
12. What is the freezing point of heavy water?
(a) 3.82 °C
(b) 1.82 °C
(c) 2.82 °C
(d) 0.82 °C
13. Occurrence of an element in 2 or more forms that differ in their crystalline or molecular structure is called:
(a) Crystallization
(b) Allotropy
(c) Distructure
(d) Hydrotropy
14. What is the term for the substance which is made of a mixture of two or more metals – for example, combining tin and copper gives the bronze?
(a) Alloy
(b) Allotropy
(c) Metallurgy
(d) Metallization
15. Brass is the mixture of:
(a) Copper and zinc
(b) Copper and silver
(c) Zinc and silver
(d) Zinc and iron
16. Which of the following is the flow of electrically charged particles through a conducting circuit due to the presence of a potential difference?
(a) Electric potential
(b) Conduction
(c) Electric Current
(d) Conductivity
17. What is called the electric current that flows for an interval of time in one direction and then in the opposite direction?
(a) Direct Current (DC)
(b) Alternating current (AC)
(c) Alpha current (AC)
(d) Altering current (AC)
18. What is called that electric current that flows in one direction and does not reverse its flow?
(a) Straight current
(b) Alternating current
(c) Direct current
(d) Volt current
19. If a conductor offers considerable resistance to the flow of current, heat results. What is produced when the heat is sufficiently intense and the conductor is strong enough to resort to the high temperature?
(a) Alpha particles
(b) X-ray
(c) Radiation
(d) Light
20. When mercury is combined with other metals, what alloy is formed?
(a) Basalt
(b) amalgam
(c) Arsenic
(d) Semi acid