Table tennis is derived from lawn tennis and was initially played as after-dinner entertainment among upper-class English families who would use whatever they could find as equipment. At the time, ...
This video explains the periodic table, containing all the known elements arranged in groups and periods. Elements in the same group of the periodic table show trends in physical properties ...
How do we calculate mass and atomic numbers? VideoHow do we calculate mass and atomic numbers? This video is an interactive lesson in calculating an atom's mass and atomic number.