Question

study guide
democritus: first idea of atoms.
dalton: atoms are indivisible spheres.
thomson: plum pudding model, discovered electron.
rutherford: gold foil experiment → nucleus.
bohr: electrons move in orbits.
activities

1. ordering: put in order → dalton, bohr, thomson, rutherford, democritus.
2. matching:

o plum pudding model →
o electrons in orbits →
o atoms indivisible →

1. multiple choice: who discovered the nucleus?

a) dalton b) bohr c) rutherford d) thomson
answer:

1. fill - in - the - blank: bohrs model said electrons travel in
2. short answer: which scientist used gold foil? what did it prove?
3. timeline sketch: draw a timeline showing atomic models.

Explanation:

Step1: Determine chronological order

Democritus was ancient, then Dalton in early - modern era, followed by Thomson, Rutherford, and Bohr in later modern era. So the order is Democritus, Dalton, Thomson, Rutherford, Bohr.

Step2: Match models to scientists

Thomson is associated with the plum - pudding model, Bohr with electrons in orbits, and Dalton with atoms being indivisible.

Step3: Answer multiple - choice

Rutherford discovered the nucleus through the gold foil experiment. So the answer is c) Rutherford.

Step4: Fill in the blank

Bohr's model said electrons travel in orbits.

Step5: Short - answer

Rutherford used gold foil. It proved the existence of a small, dense, positively - charged nucleus within the atom.

Answer:

1. Democritus, Dalton, Thomson, Rutherford, Bohr
2. Plum pudding model → Thomson; Electrons in orbits → Bohr; Atoms indivisible → Dalton
3. c) Rutherford
4. orbits
5. Rutherford used gold foil. It proved the existence of a small, dense, positively - charged nucleus within the atom.
6. (Sketching a timeline is beyond text - based response, but it would have Democritus first, then Dalton, Thomson, Rutherford, and Bohr with their respective atomic models marked at appropriate time points)