Why is the coefficient of static friction always greater than the coefficient of kinetic friction?

Because in static friction there is more time or enough time for interlocking of irregularities where as there is minimum time for interlocking of irregularities so that kinetic friction is less than that of static friction

answer: option (b) is the correct answer.

explanation:

a covalent bond is formed by sharing of electrons. whereas polarity arises due to difference in electronegativity of two atoms.

therefore, more is the electronegativity of an atom which combines with the titanium, more readily it will induce a partial positive and negative charge.

thus, out of the given options fluorine is most electronegative and has an incomplete octet. therefore, it will readily combine with titanium to share the electrons and complete its octet.  

its first and third is your answer i did the qustion the fourth isnt right