Practice question · Multiple choice
Almost all alpha particles passed straight through the gold foil, but about 1 in 8000 rebounded. What does the rebounding minority establish?
Hints
- Ask what could turn back a fast, heavy, positive particle.
- Diffuse charge cannot do it, only a dense concentrated one can.
Show the answer
D. Positive charge and mass are concentrated in a tiny nucleus
Why
A thinly spread positive charge exerts a weak force everywhere and could never reverse a fast alpha particle. Only a small, dense, highly charged nucleus can, and the rarity of the rebound shows how tiny that target is.
Practise Atomic Models and Isotopes
The app has 4 more questions on this lesson, and keeps your place in the course. Chemistry I is free to start.
More questions on Atomic Models and Isotopes
- An isotope has mass number A = 56 and atomic number Z = 26. How many neutrons does its nucleus contain?
- Two isotopes of the same element show almost identical chemical behaviour.
- Chlorine is 75.77 % chlorine-35 (mass 35 u) and 24.23 % chlorine-37 (mass 37 u). Compute its average atomic…
- Match each subatomic particle to its defining property.
- Which statements about isotopes are correct?
- The periodic table lists the atomic mass of chlorine as 35.45 u, yet no single chlorine atom possesses this…
- Why could Thomson's plum-pudding model not survive the gold-foil result?
- Place these atomic models and discoveries in chronological order.