1.
Which one of the following process is used to purify a soluble solid?
Answer : B. Crystallisation
2.
Crystals having low melting points are in
Answer : D. Metallic bond
3.
The working of a quartz crystal in the watch is based on the
Answer : C. Piezo-electric effect
4.
I. Graphite is an allotrope of carbon II. Diamond is metal
Answer : D. true,false
5.
Nodes are
Answer : B. positions of no displacement
6.
The lowest level energy band in a solid is called
Answer : A. Valence band