



The repulsion is in the order: lp-lp > lp-bp > bp-bp.
In PF3, there is a lp-lp repulsion, the angle of PF3 will be less than BF3.
The geometry of BF3 is trigonal planar while NH3 is tetrahedral
The sequence will therefore be, BF3> NH3>PF3
I3- is a linear molecule therefore, the angle is 180 degree.
The overall order will be I3- > BF3> NH3>PF3
Match List-I with List-II and select the correct option: 
The bond angles \( b_1, b_2, b_3 \) in the above structure are respectively in \( ^\circ \):

If $ \theta \in [-2\pi,\ 2\pi] $, then the number of solutions of $$ 2\sqrt{2} \cos^2\theta + (2 - \sqrt{6}) \cos\theta - \sqrt{3} = 0 $$ is:
A thin transparent film with refractive index 1.4 is held on a circular ring of radius 1.8 cm. The fluid in the film evaporates such that transmission through the film at wavelength 560 nm goes to a minimum every 12 seconds. Assuming that the film is flat on its two sides, the rate of evaporation is:
The major product (A) formed in the following reaction sequence is

Covalent bonds can be characterized on the basis of several bond parameters such as bond length, bond angle, bond order, and bond energy (also known as bond enthalpy). These bond parameters offer insight into the stability of a chemical compound and the strength of the chemical bonds holding its atoms together.
For example, The H—H bond enthalpy in hydrogen is 435.8 kJ mol-1. \
Bond order of H2 (H —H) =1
Bond order of 02 (O = O) =2
Bond order of N2 (N = N) =3
Read More: Chemical Bonding and Molecular Structure