BRAINCAKEParticles
Revision notes for Particles in OCR Combined Science A (J250). Every lesson in BrainCake comes with R.E.C.I.P.E. recall steps, a quick check and spaced reviews.
- The particle model and changes of stateThe particle model explains the three states of matter by picturing every substance as made of tiny particles.
- Physical and chemical changesIn a physical change the substances stay the same.
- Limitations of the particle modelThe simple particle model pictures particles as small, hard, inelastic spheres, like tiny bowling balls.
- How the atomic model has changedScientists change a model when new evidence does not fit the old one.
- The nuclear model of the atomAn atom has a small, positively charged nucleus at its centre.
- The size of atoms and small moleculesAtoms are extremely small.
- Relative charge and mass of subatomic particlesAtoms are made of three types of subatomic particle: protons, neutrons and electrons.
- Protons, neutrons and electrons in atoms and ionsThe atomic number is the number of protons in an atom.