The tail side (the technical term is "reverse") of the current US penny is the "Union Shield", a shield that has vertical stripes and "E Pluribus Unum" written across the top of it, partially obscured by scrollwork saying "One Cent".
Up until 2009, the most recent design of th e US penny had the Lincoln Memorial on the reverse (this is the same building depicted on the back of the five dollar bill). In 2009, four "commemorative" designs were issued for the bicentennial of Lincoln's birth. Prior to the Lincoln Memorial reverse, the penny featured two stalks of wheat.
The nickel's reverse is a depiction of Monticello, Jefferson's home. In 2004 and 2005 five commemorative reverses (for the approximate bicentennial of the Lewis and Clark expedition) were issued.
It is worth something to an error collector, but not enough to finance your retirement. Might ge enough to get a cup of coffee at the Kwik Shop.
Nickel(II) oxide has the formula NiO.
Why do comets have tails
No, mosquitoes do not have tails.
You may be able to sell it on eBay for under $5 (since these are readily available as novelty items for around $6). Because of the way the US Mint manufactures coins, it's almost impossible to have a real two-headed or two-tailed coin of any denomination. There are situations where you may see a mirror image on one side of a coin, eg a standard obverse or "heads" side on one side and a reversed incuse image on the opposite side, but it will not look like a two-headed coin. Certain coin designs may also have on the "tails" side a different person's head. I don't recall that ever happening with the US nickel, though I could be wrong. The other side will appear completely different, though, from the "heads" side.
There are eight possible results when flipping three coins (eliminating the highly unlikely scenario of one or more coins landing on their edge): Dime - Heads / Nickel - Heads / Penny - Heads Dime - Heads / Nickel - Heads / Penny - Tails Dime - Heads / Nickel - Tails / Penny - Heads Dime - Heads / Nickel - Tails / Penny - Tails Dime - Tails / Nickel - Heads / Penny - Heads Dime - Tails / Nickel - Heads / Penny - Tails Dime - Tails / Nickel - Tails / Penny - Heads Dime - Tails / Nickel - Tails / Penny - Tails
On the obverse (heads) side is an image of President Thomas Jefferson, and the reverse (tails) shows his home Monticello.
The building on the reverse [tails] side of the Jefferson nickel is the home of Thomas Jefferson, Monticello, located in Charlottesville, Virginia. There is a caption right under the building that identifies it.
The Liberty Nickel is a USA 5 cent coin which was minted from 1883 to 1912, bearing the image of Lady Liberty on the obverse [heads] side of the coin and a large letter "V" on the reverse [tails] side of he coin.
The tails side is the side without the head on it.
The standard nickel has the Jefferson Memorial on the back of it. There have been a number of new nickels issued with other pictures.
The coin needs to be seen and weighed, take it to a coin dealer. Likely the coin has been altered by some process out side the Mint and is only face value.
The mint mark on a 1939 Jefferson Nickel is located on the obverse (tails) side of the coin, just to the right of Monticello (the building) between the rim and the building. If there is no mark there then the coin was produced at the U.S. Mint facility in Philadelphia, Pennsylvania.
Side to side
The silver and the nickel 3 cent coins minted in 1865 are 2 different coins and look different. The silver 3 cent coin minted in 1865 has a star on the obversed [heads] side of the coin and the reverse [tails] side has a large letter "C" with a Roman Numeral III [3] inside of it. This coin is smaller than a present day dime. The nickel 3 cent coin minted in 1865 has on the obverse [heads] side of the coin an image of Lady Liberty facing left while the reverse [tails] side of the coin has a large Roman Numeral III [3] surrounded by a wreath. This coin is the same size as todays dime.
The right side
Whales' tails move up and down when they swim, just like peoples' legs.