According to the periodic table entry, how many electrons does nickel have in its valence level? A.2
B.8
C.16
D.28

When you drop a pebble from height a it reaches the ground with speed v if there is no air resistance. from what height should you drop it so it will reach the ground with three times the speed? (a) 9m (b) 3m (c) 6m (d) 18m

Arod of some material 0.20 m long elongates 0.20 mm on heating from 21 to 120°c. determine the value of the linear coefficient of thermal expansion [in (degrees c)^-1] for this material.

How is sound energy produced a. vibrating objects b. objects being heated c. temperature differences d. stationary objects