Exercise 3

Question 6 :

The main active constituent of tea and coffee is


A). nicotine
B). chlorophyll
C). caffeine
D). aspirin
Answer : Option C

Question 7 :

The hardest form of carbon is


A). coke
B). graphite
C). diamond
D). charcoal
Answer : Option C

Question 8 :

The most important ore of aluminium is


A). bauxite
B). magnetite
C). haematite
D). monazite
Answer : Option A

Question 9 :

The hottest part of the gas flame is known as


A). luminous zone
B). dark zone
C). blue zone
D). non-luminous zone
Answer : Option D

Question 10 :

The human body is made up of several chemical elements; the element present in the highest proportion (65%) in the body is


A). carbon
B). hydrogen
C). oxygen
D). nitrogen
Answer : Option C