What do bio-pesticides include?

$A$ circular disc of radius $R$ is removed from a bigger circular disc of radius $2R$ such that the circumferences of the discs touch. The centre of mass of the new disc is at a distance $\alpha R$ from the centre of the bigger disc. The value of $\alpha$ is

According to the kinetic theory of gases,when two molecules of a gas collide with each other,then:

Which of the following forms a colloidal solution in water?

The correct order of the $O-O$ bond length in $O_2, H_2O_2$,and $O_3$ is

The Biuret test is not given by: