The copper in an older cent (before 1983) is worth almost two cents as scrap metal. Cents are now made of zinc with a very thin copper coating.
Copper
In 1943 the US Mint briefly replaced the copper penny then in use with a steel penny, due to the wartime copper shortage.
US cents minted since late 1982 are composed of a core of 99.2% zinc and 0.8% copper with a plating of pure copper.
Those are 95 percent copper. A US penny weighs 3.11 grams. Of that, 2.9545 grams is copper.
copper
The last year for copper US pennies was 1982.
In 1961 pennies were made of 95% copper and 5% zinc.
A US copper penny is exactly 2 cm wide.
A 1983 Lincoln cent is actually copper plated zinc, 1982 was the last year for copper pennies. It's just a penny.
You cannot recycle a US copper penny as only the mint is legally allowed to melt the currency. It is a Federal offense to melt any US currency for sale despite the copper penny being worth less than it's face value. The Federal mint is losing money on every copper penny it mints and keeps in circulation today, which is one of the strongest reasons for ending it's circulation.
2 cents.
A 1994 US cent is zinc not copper, spend it.