Cry $II$ Ab and Cry $I$ Ab produce toxins that control:

The element having the greatest difference between its first and second ionization energies is

The correct sequence of increasing covalent character is represented by

The rate constant for the reaction,$2 \ N_2O_{5(g)} \longrightarrow 2 \ N_2O_{4(g)} + O_{2(g)}$ is $4.98 \times 10^{-4} \ s^{-1}$. What is the order of reaction?

The gravitational force acting on a particle,due to a solid sphere of uniform density and radius $R$,at a distance of $3 R$ from the centre of the sphere is $F_1$. $A$ spherical hole of radius $(R / 2)$ is now made in the sphere as shown in the figure. The sphere with hole now exerts a force $F_2$ on the same particle. Ratio of $F_1$ and $F_2$ is

$A$ beam of light $AO$ is incident on a glass slab $(\mu = 1.54)$ in a direction as shown in the figure. The reflected ray $OB$ is passed through a Nicol prism. On viewing through the Nicol prism,we find on rotating the prism that: