Modern Physics PHY 36001

Question 1.

It is impossible to see an atom owing to the diffraction of light?

       True
       False

Question 2.

If atoms are stable, then there must be forces that counter-act each other. Otherwise the atom would colapse on itself, or blow itself apart.

       True
       False

Question 3.

If a neutral atom contains Z electrons, it must contain an exactly equal amount of positive charge.

       True
       False

Question 4.

When alpha particles are scattering from an atom, the alpha particles which come closest to the nucleus are just those of highest kinetic energy.

       True
       False

Question 5.

If the distance of closest approach was less than the radius of the nucleus, the Rutherford scattering formula (Eq. 6.18) would be wrong.

       True
       False

Question 1.

In scattering, the impact parameter b is defined as the

      a. maximum kinetic energy of the scattering projectile.
      b. distance of closest approach between projectile and target.
      c. closest distance between projectile and target if there were no deflection.
      d. distance between projectile and target for which there is maximal deflection.

Question 2.

We know that the Rutherford model of the atom is superior to the Thompson model because when alpha particles are scattered from atoms

      a. the deflected angle is always large.
      b. some alpha particles are deflected to large angles.
      c. they are usually observed with kinetic energy between 5 and 10 MeV.
      d. the deflected angle is usually small.