Is SiH4 polar or nonpolar? Iis NoBr polar or nonpolar ? IsNO2F polar or nonpolar?
The correct answer and explanation is:
SiH₄ (Silane) is nonpolar. This is because SiH₄ has a tetrahedral molecular geometry, with silicon at the center bonded to four hydrogen atoms symmetrically arranged around it. The individual Si-H bonds are slightly polar due to the difference in electronegativity between silicon and hydrogen, but the symmetrical arrangement of the bonds cancels out any dipole moments. This results in a nonpolar molecule.
NOBr (Nitrosyl bromide) is polar. This molecule has a bent or angular geometry, where the nitrogen atom is bonded to both an oxygen atom and a bromine atom. The electronegativity difference between nitrogen (3.04) and oxygen (3.44), and nitrogen and bromine (2.96) creates polar bonds. Due to the bent shape of the molecule, the dipoles do not cancel out, leading to a net dipole moment, making NOBr polar.
NO₂F (Nitrogen dioxide fluoride) is polar. The molecule adopts a bent shape, similar to that of NO₂, where the nitrogen is bonded to two oxygen atoms and one fluorine atom. The electronegativity differences between nitrogen (3.04), oxygen (3.44), and fluorine (3.98) create polar bonds. The arrangement of these bonds leads to an unequal distribution of charge, causing a net dipole moment. Thus, NO₂F is polar.
In summary, SiH₄ is nonpolar due to its symmetrical tetrahedral geometry, while NOBr and NO₂F are both polar due to their bent molecular shapes and differences in electronegativity between the atoms. The key factor in determining the polarity of a molecule is the symmetry of the molecular geometry, which affects how dipole moments combine.