Answer:
4. trigonal planar symmetry.
Explanation:
The sp2 hybridization is formed with one s and two p atomic orbitals and form trigonal planar symmetry. In sp2 hybridization, there are same valence shell in both the orbitals and it gives three equivalent sp2 hybridized orbitals that are separated by 120 degrees giving trigonal planar symmetry.
Hence, the correct answer is "4. trigonal planar symmetry.".
Mercury expands when it is heated. This process is called thermal expansion.
These are called subscript number.
That is the number below the normal line of test are called subscript number.
This number indicate the indicate the number of atoms of the element present in the chemical formula.
In both of these C₆H₁₂O₆ and H₂O, the number written below the line of the text are called subscript numbers.