Masses of two isobars `._(29)Cu^(64)` and `._(30)Zn^(64)` are `63.9298 u` and `63.9292 u`, respectively. It can be concluded from these data that .

Mases of two isobars ._(29)^(64) Cu and ._(930)^(64)Zn are 63.9298 amu and 63.9292 amu respectively. It can be concluded form these data that:

A current of 9.65 A is drawn from a Daniell cell for exactly one hour. If molar masses of Cu and Zn are 63.5 g mol^(-1) and 65.4 g mol^(-1) , respectively, the loss in mass at anode and gain in mass at cathode respectively are

The average atomic mass of copper is 63.5 . It exists as two isotopes which are ._(29)^(63)Cu and ._(29)^(65)Cu . Calculate the percentage of each isotope present in it.

An object is placed in front of two convex lenses one by one at a distance u from the lens. The focal lengths of the lenses are 30 cm and 15 cm respectively. If the size of image formed in the two cases is same, then u is