Structure of Atom

Assertion : The chemical properties of
different isotope are same.
Reason : Isotopes having same number of
neutron.

A bulb is emitted electromagnetic radiation of \(660 \mathrm{~nm}\) wavelength. The total energy of radiation is \(3 \times 10^{-18} \mathrm{~J}\). The number of emitted photon will be
$$\left(h=6.6 \times 10^{-34}\right) \mathrm{J} \times ...

The work function of a metal is \(4.2 \mathrm{~eV}\). If radiation of 2000 \(\mathop A\limits^o\) fall on the metal then the kinetic energy of the fastest photoelectron is