zinc is 97.5% of the penny and copper is 2.5% of the penny
Penny is not a proper noun.
The plural form for penny is pennies or pence.
A penny earned is a penny saved means the money you save (and you don't spend) then it is earned. Because you don't waste it so it's practically saved.
That is Jimmy's penny.
Like penny stocks, penny margin describes very small margin just like the typical value of a coin of one cent.
Copper of course!
A Penny is not a compound. It's just one word.
i herd some pennies contain zinc
A penny is a compound, not an element. Pennies are typically made of a combination of mostly zinc and copper, which are two different elements.
A penny can be shiny when it is new, but it typically becomes dull over time due to oxidation and wear. Regular handling and exposure to the elements can cause the penny's surface to lose its shine and become more dull in appearance.
With the exception of cents struck in 1943 and 1944, modern cents were composed of copper zinc and tin. In 1982 it was changed to zinc with a plating of copper.
When a penny comes in contact with carbon, such as in the form of graphite in a pencil, the two materials do not chemically react. The friction between the penny and carbon can cause a transfer of material, leaving a mark on the penny.
Copper naturally turns from a red into a brownish colour when exposed. A tarnished penny will seem dark brown. It could also possibly mean corrosion where the penny turns a green colour from exposure to the elements. If you look at a brand new penny, it will be a bright red colour, if you look at a circulated penny it will be a dull brown.
The coinage elements are the metals that are used to make coins. They are the three metals from Group 11 of the periodic table - copper, silver and gold.
basically, the zinc electrons in the NaOH solution coat the copper penny and then when you wave it over a Bunsen burner, the two metals form an alloy (a homogeneous mixture with two or more elements) and make brass, not gold.
Most copper pennies (cents) turn brown after they have been handled and exposed to the elements for a few months. A 'red' penny is one that has been protected since it was new and retains its original copper color.
The singular possessive of penny is penny's, as in "penny's worth".