| Metal | Li | Na | K | Mg | Cu | Ag |
| Wo/eV | 2.42 | 2.3 | 2.25 | 3.7 | 4.8 | 4.3 |
The number of metals which will show photoelectric effect when light of wavelength 400nm falls on it is____
Given: h = 6.6 × 10-34 J s
c = 3 x 108 m s-1
e = 1.6 x 10-19 C

In the first configuration (1) as shown in the figure, four identical charges \( q_0 \) are kept at the corners A, B, C and D of square of side length \( a \). In the second configuration (2), the same charges are shifted to mid points C, E, H, and F of the square. If \( K = \frac{1}{4\pi \epsilon_0} \), the difference between the potential energies of configuration (2) and (1) is given by:
Given below are two statements:
Statement I:
will undergo alkaline hydrolysis at a faster rate than 
Statement II:
In
intramolecular substitution takes place first by involving lone pair of electrons on nitrogen.