Yes, they're still available from banks and have never been withdrawn from circulation. They're just not in common use in most parts of the country.
It depends on their date and the country that minted them. There's no general rule.
50 two cent coins, they exist.
An Australian 50 cent coin weighs 15.55 grams. There would be 64 x 50 cent coins in one kilogram.
There were 4,337,200 Australian 1997 50 cent coins minted.
Four 5 cent coins and three 10 cent coins.
A 50 cent coin and three 10 cent coins.A 50 cent coin, a 20 cent coin and two 5 cent coins.Four 20 cent coins.
One 50-cent coin, two 10-cent coins, and two 1-cent coins.
Current US denominations are: 1 cent, 5 cent, 10 cent, 25 cent, 50 cent & $1.00 coins.
Germany uses coins that are based on the euro. There are two euro coins, one euro coins, 50 cent euros, 20 cent, 10 cent, 5 cent, and 1 cent euro coins.
20 cent coins
There is no straightforward answer, you can make it with 50 or 45 coins quite easily if you use 50 one-cent coins or 49 one-cent coins and a 5-cent coin. You could bend the meaning of the question using non-US currencies, or by trading, etc.
1863 only had a mintage of 21,000 3-cent coins.
If it is a collection of 50 cent coins, it could be worth a lot, or not that much. It depends on the dates of the coins and the condition. 50 cent coins from before 1965 are worth more because they are 90% silver.