Na2O3, HNO2, Na2OH, CuO
(b) Name the following symbols. (2 marks)
Au, Sn, Pt, Cr
VI.Answer ANY THREE questions. (12 marks)
(a) Describe an experiment of a physical change on passing on passing electricity through a copper rod.
(b) In a molecule of a compound there are two atoms of hydrogen and two atoms of another element .The relative mass of the molecule is 34.What is relative mass of another
. 1 only B. 2 only C. 3 only D. 1 and 2 only E.2 and 3 only
- p2+q2=…………
A.(p+q)2 B.(p-q)(p-q) C.(p-q)2+2pq D.(p-q)2-2pq E. None of these
17.If a2+2ka +16 is a perfect square , then k=…..
pen to that of a pencil is
A. 1:3 B. 1:4 C. 3:1 D. 4:1 E. 16:3 - The ratio of the area of a circle of radius 7 cm to the area of a circle of radius 14 cm is
A. 1:2 B. 2:3 C. 3:5 D. 4:9 E. 1:4