the sphere neon
When an electrical current is passed through Neon, it produces an unmistakable bright reddish-orange light used in signs. Neon lights are popular because their bright colorful lights attract customers.
Neon is a chemical element with symbol Ne and atomic number 10.It has ten protons, ten neutrons and ten electrons. It is in the noble gases group (18) of the periodic table. As a noble gas, under standard conditions, Neon is chemically inert and forms no compounds with other chemicals.
Neon is a colorless, odorless, inert monatomic gas, with about two-thirds the density of air.
Although neon is a very common element in the universe and solar system (it is fifth in cosmic abundance after hydrogen, helium, oxygen and carbon), it is very rare on Earth. It composes about 18.2 ppm (parts per million) of air by volume. The reason for neon's relative scarcity on Earth and the inner (terrestrial) planets is that neon is highly volatile (becomes a gas at a low temperature) and forms no compounds to fix it to solids Neon is monatomic (one atom), making it lighter than the molecules of diatomic (two atoms) nitrogen and oxygen which form the bulk of Earth's atmosphere. A balloon filled with neon will rise in air, but more slowly than a helium balloon.
Neon was discovered in 1898. A sample of air was chilled until it became a liquid,
then warmed the liquid and captured the gases as they boiled off. The characteristic
brilliant red-orange color emitted by gaseous neon when excited electrically was
noted immediately. Neon plasma (plasma means a gas through which an electric
current is passing) has the most intense light discharge at normal voltages and
currents of all the noble gases.
In 1912, Georges Claude, an engineer based in Paris began selling neon discharge
tubes as eye-catching advertising signs and was soon successful. Neon tubes were
introduced to the U.S. in 1923 with two large neon signs bought by a Los Angeles
Packard car dealership. The glow and arresting red color made neon advertising
completely different from the competition.
Problem Set (example)
1, If Neon is 18.2 parts per million in the air, how many cubic yards of air would you need to have enough Neon to make a sign 3 feet long out of glass tubing with an interior diameter of ½ inch. Assume same density of Neon and air.
One cubic yard of air = 46,656 cubic inches
Tubing volume = 36 x 22/7 x 0.252 = 7.07 cubic inches (rounded)
Neon density in air = 18.2/1,000,000
Neon volume in one cubic yard of air = 46,656 x 18.2/1,000,000 = 0.85 cubic inches (rounded)
Number of cubic yards of air needed to supply enough Neon for the sign = 8.33 (rounded).