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Combined Science: Physics

GCSE · Edexcel · foundation

QuestionsFlashcards

Expressing Quantities & SI Units
- Units & Prefixes
  8
- Conversions & Standard Form
  6

Atomic Structure
Radioactive Decay
Dangers of Radiation
- Dangers of Radiation
  5
- Contamination & Irradiation
  6

Magnetism
Electromagnetism & The Motor Effect
- Magnetic Fields in Wires
  6
- Magnetic Fields in Solenoids
  6

Transformers & the National Grid
- The National Grid
  5
- The Ideal Transformer Equation
  3

Developing Models of the Atom Flashcards

All 6 cards in this deck

Describe the plum pudding model of the atom.: A ball of positive charge with negative electrons embedded in it.
What were the results of Rutherford's alpha particle scattering experiment?: Most alpha particles passed straight through the foil, some were deflected, and a very few bounced straight back.
Why was the plum pudding model replaced after the alpha scattering experiment?: It could not explain the results; the new evidence showed the atom is mostly empty space with a tiny, dense, positively charged nucleus, so the model had to be changed.
True or false? A scientific model of the atom is changed or replaced when new experimental evidence cannot be explained by it.: True. Models are accepted only while they fit the evidence, so new results can force a change.
How did Rutherford know the nucleus must be positively charged?: Some positive alpha particles were pushed back (repelled) by it, and like charges repel.
What did Niels Bohr add to the nuclear model of the atom?: That electrons sit in fixed energy levels at set distances from the nucleus (the Bohr model).