Step 1: Analyze Option (1) - BF₃
BF₃ is a planar molecule with B-F bonds arranged symmetrically. The dipole moments of the B-F bonds cancel each other, resulting in a zero dipole moment for the molecule. Thus, option (1) is false.
Step 2: Analyze Option (2) - Dipole Moment of NF₃ vs NH₃
In NF₃, fluorine is more electronegative than nitrogen, and the dipoles do not cancel, so NF₃ has a non-zero dipole moment.
NH₃ also has a non-zero dipole moment, but NF₃ has a greater dipole moment due to the greater electronegativity of fluorine. Thus, option (2) is true.
Step 3: Analyze Options (3) and (4)
Option (3): The Carbonate Ion (CO₃²⁻)
The carbonate ion (CO₃²⁻) has three resonance structures with equal contribution, so option (3) is true.
Option (4): The Ozone Molecule (O₃)
The ozone molecule (O₃) has two major resonance structures, so option (4) is true.
Step 4: Conclusion
The correct answer is: Option (4): Three canonical forms can be drawn for the CO₃²⁻ ion.
Complete the following reactions by writing the structure of the main products:
A sphere of radius R is cut from a larger solid sphere of radius 2R as shown in the figure. The ratio of the moment of inertia of the smaller sphere to that of the rest part of the sphere about the Y-axis is :
The current passing through the battery in the given circuit, is:
A bob of heavy mass \(m\) is suspended by a light string of length \(l\). The bob is given a horizontal velocity \(v_0\) as shown in figure. If the string gets slack at some point P making an angle \( \theta \) from the horizontal, the ratio of the speed \(v\) of the bob at point P to its initial speed \(v_0\) is :