The ratio of protons to neutrons may vary but in a neutral atom the number of protons = the number of
a. neutrons
b. electrons
c. positrons
d. protons outside the nucleus

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.  

well in order to answer this question you have to provide more information < 3