Complete the paragraph to describe the characteristics of a silicon tetrahydride molecule (sih4). the lewis structure and table of electronegativities are given.

The bonds present in SiH4 are polar due to difference in electronegativity between Silicon and hydrogen

The molecular shape is tetrahedral

the hybridization is sp3

In spite of the polarity of bonds of SiH4, the molecule is non polar due to overall zero dipole moment in the molecule.

The dipole moment is the product of charge and distance between charged particles. It is a vector quantity and thus it is directional

All the four bonds of Si-H are polar however the dipoles of each bond cancel each other and the net dipole is zero

hence the molecule is non polar

So answers are

a) Polar

b) tetrahedral

c) non polar

alkaline metals are lithium, sodium, rubidium, potassium, cesium and francium.

alkali metals have electronegativity from 0.7 to 1, lowest in periodic table of elements, which means that alkali metals (i group in periodic table) has positive oxidation number in compounds.

electronegativity is a chemical property that describes the tendency of an atom to attract a shared pair of electrons towards itself.

alkaline metals (far left in main group) have lowest ionizations energy and easy remove valence electrons,

for example, potassium is the alkali metal and has a single valence electron in the outer electron shell.

electron configuration of potassium is: ₁₉k 1s²2s²2p⁶3s²3p⁶4s¹.

they can not exist alone in nature, because they are very reactive.