3. Atomic structure

Available for over a year

In this episode, Dr Sunayana Bhargava and Tulela Pea split the atom to look at the mass and charge of protons, neutrons and electrons. They also define the atomic mass of an atom. Suitable for: AQA, Edexcel, OCR. For more information on atomic structure, check out the BBC Bitesize website: https://www.bbc.co.uk/bitesize/guides/zwn8b82/revision/3 Key learning objectives discussed in this episode include: - Atoms are very small, having a radius of about 0.1 nm (1 x 10-10 m). The radius of a nucleus is less than 1/10 000 of that of the atom (about 1 x 10-14 m). - The relative electrical charges of the particles in atoms – proton +1, neutron 0, electron -1. - In an atom, the number of electrons is equal to the number of protons in the nucleus. Atoms have no overall electrical charge. - The number of protons in an atom of an element is its atomic number. All atoms of a particular element have the same number of protons. Atoms of different elements have different numbers of protons. - Almost all of the mass of an atom is in the nucleus. - The relative masses of protons (1), neutrons (1) and electrons (very small). The sum of the protons and neutrons in an atom is its mass number. - Students should be able to calculate the numbers of protons, neutrons and electrons in an atom or ion, given its atomic number and mass number. - The electrons in an atom occupy the lowest available energy levels. The electronic structure of an atom can be represented by numbers or by a diagram.