Rutherford's experiment on scattering of $$\alpha-particles$$ showed for the first time that the atom has

The correct order of second ionisation potential of carbon, nitrogen, oxygen and fluorine is

The angle between two convalent bonds is maximum in ________. (CH₄, H₂O, CO₂)

If a molecule MX₃ has zero dipole moment, the sigma bonding orbitals used by M (atomic number < 21) are