Using particle accelerators, scientists often use to synthesize heavier elements.
a) gamma rays
b) alpha particles
c) beta particles

      To synthesize heavier elements scientists often use alpha particles in particle accelerators.

Hence the right option is B.

alpha particles

A) gamma rays

B) alpha particles  

C) beta particles

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.