Question

what was the main conclusion j.j. thomson drew from his cathode ray tube experiments?
atoms are solid, indivisible spheres.
atoms are mostly empty space.
atoms have a dense, positively charged nucleus.
atoms contain negatively charged particles, which he called electrons.
ernest rutherfords gold foil experiment involved firing positively charged alpha particles at a thin sheet of gold foil. what was the most surprising observation from this experiment?
all of the alpha particles passed straight through the foil.
most of the alpha particles were deflected at very small angles.
a small fraction of the alpha particles were deflected at large angles or bounced back.
the gold foil emitted electrons when struck by the alpha particles.
according to john daltons atomic theory, what is the fundamental characteristic of atoms?
they are indivisible and indestructible.
they are constantly in motion and can change into different elements.
they are all identical in mass and properties.
they are composed of smaller particles like electrons and protons.

Explanation:

• J.J. Thomson's cathode ray tube experiments: He discovered electrons. The cathode rays were deflected by electric and magnetic fields, showing they were negatively - charged particles (electrons) within atoms.
• Rutherford's Gold Foil Experiment: The surprising result was that a small fraction of alpha particles were deflected at large angles or bounced back. This led to the nuclear model of the atom.
• John Dalton's atomic theory: Dalton proposed that atoms are indivisible and indestructible.

Answer:

• For J.J. Thomson's conclusion: Atoms contain negatively charged particles, which he called electrons.
• For Rutherford's experiment: A small fraction of the alpha particles were deflected at large angles or bounced back.
• For Dalton's theory: They are indivisible and indestructible.