This lesson explains what is represented by the atomic number, and how it varies from one element to the next. It is 6 of 7 in the series titled "Atomic Number."

This lesson explains what is represented by the atomic number, and how it varies from one element to the next. It is 5 of 7 in the series titled "Atomic Number."

This lesson demonstrates how to represent rational numbers using variables. It is 2 of 9 in the series titled "Representing Rational Numbers Using Variables."

This lesson will introduce quantum numbers, their symbols, and what they represent. It is 2 of 3 in the series titled "Quantum Numbers."

Slideshow looking at the history of models of the atom, including those proposed by John Dalton, J.J. Thomson, Ernest Rutherford, Niels Bohr, and James Chadwick. Discusses subatomic particles, including the numbers of protons, neutrons,...

" Ethnolinguistic Groups - Almost all inhabitants of mainland China are of Mongoloid stock, and ethnic distinctions in the country are largely linguistic rather than racial. The Han comprise nearly 95 percent of the population; the...

A mask. Masks were worn by Greek and Roman actors in nearly all dramatic representations. This custom arose undoubtedly from the practice of smearing the face with certain juices and colours, and of appearing in disguise, at the...

A mask. Masks were worn by Greek and Roman actors in nearly all dramatic representations. This custom arose undoubtedly from the practice of smearing the face with certain juices and colours, and of appearing in disguise, at the...

A shoe or boot, anything adapted to cover and preserve the feet in walking. The use of shoes was by no means universal amount the Greeks and Romans. The Homeric heroes are represented without shoes when armed for battle. Socrates,...

A torch. In the annexed woodcut, the female figure is copied from a fictile vase. The winged figure on the left hand, asleep and leaning on a torch, is from a funeral monument at Rome. The other winged figure represents Cupid as Lethaus...

Major General Sheridan riding along the lines after the Battle of Fisher's Hills, Va., September 22nd, 1864. Our illustration representing General Sheridan riding along the lines after his victory at Fisher's Hill is indeed a spirited...