Question

is SF4 is a polar molecules,if yes then how and if no then why

Answer 1

SF4 Have four S-F bonds ,since F is the most electronegative and S is moderately electro negative.So,S-F is a polar  bond. Shape of SF4 The shape of  the molecule is see-saw with the presence of  the lone pair in the plane of the central atom.The lone pair also leads to the creation of  a strong dipole moment.