Khan Academy: Period Trend for Electron Affinity

Explanation of the ionization energy required for different groups on the Periodic Table. [10:18]

Electronegativity is defined and compared to electron affinity. Trends based on groups and periods are also explored. [9:54]

An example of graphing second order rate data to see a linear relationship, and calculating rate constant k from the slope is introduced from Khan Academy. [8:02]

A Khan Academy lesson identifies the risk factors for strokes. [11:37]

David explains what affects the period of a mass on a spring (i.e. mass and spring constant). He also explains what does not affect the period of a mass on a spring (i.e. amplitude and gravitational acceleration). [8:10]

Electron affinity is defined. Electron affinities of various elements are compared. [11:39]

Learn the difference between electronegativity and electron affinity. Group and period trends are also discussed in relation to atomic radii. [9:54]

A video lecture explaining the movement of the electrons around the nucleus in orbitals. Video describes the orbital's energy shell and shape. Also discussed is the connection of the location of the electrons to the periodic table. [13:37]

An explanation of how to calculate the number of electrons and their orbitals for the first four shells. [12:37]

Learn about Thomson's cathode ray experiment and the plum pudding model and Rutherford's gold foil experiment.