Uranium-238 decays by alpha emission. what is the mass number of the resulting element?

The answer to your question is 234.

Explanation:

Alpha emission is a type of radioactive composed on two positive charges and two neutrons, its total mass is 4, the element with these characteristics is Helium.

Then,

        Uranium-238 ⇒   Thorium-234 + Helium-4        

             Because  234 + 4 = 238

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.