Three molecules of type a, three of type b, three of type c, and three of type d are to be linked together to form a chain molecule. one such chain molecule is abcdabcdabcd, and another is bcddaaabdbcc. (a) how many such chain molecules are there? [hint: if the three a's were distinguishable from one another— a1, a2, a3— and the b's, c's, and d's were also, how many molecules would there be? how is this number reduced when the subscripts are removed from the a's? ]

Alpha particles have positive charge, beta particles have negative charge, and answer 4 just doesn’t make sense. thus, you are left with only one possible answer.

Vander waals forces are inter molecular bonds that exist within molecules of the same substance. a water molecule is made up of oxygen and hydrogen atoms which share electrons between each other. the vander waals forces are forces that exist between multitude of different  molecules of water. dipole dipole forces is the type of vander waals force that exist in water. the oxygen atom which is more electronegative pulls the shared electron closer to itself thus generating a partial negative charge while the hydrogen acquire a partial positive charge. these two different charges causes attraction to occur in water molecules.

Tell me the answer choices and i would be able to answer. : )

Moles = mass/molar mass by this formula 458/207+32 you should get your answer the ans. is 1.916 mol to 4 sig. fig.