Yes it is, 40% silver
No, the last year for 40% Kennedy halves was 1970. 1971 to date are clad copper nickel.
Silver: 12.5 g; Silver-clad: 11.5 g; Copper-nickel clad: 11.34 g
A Kennedy Half Dollar that was minted in 2007 and carries a mint mark of "S," was produced in clad and silver. The clad in a proof state is worth: $4; in silver, the value is: $7.00.
The 1970 half is 40% silver and currently worth about about $4.70.
Some versions of the bicentennial proof half dollar contain 40% silver, while others are the same copper clad as circulating halves. The clad version has a visible copper ring around the edge.
It depends on the type. There were two types: silver-clad and a copper-nickel-clad. Silver-clad contains 0.14792 ounces of pure silver. All have an S mint mark. Copper-nickel-clad does not contain any silver. They can have a D, S, or no mint mark.
1964 was the only year JFK halves were made of 90% silver alloy. The composition was changed to 40% silver clad in 1965, and to copper-nickel clad in 1971. A 1964 Kennedy Half Dollar contains .3617 ounces of pure silver. Multiply this by the spot price of silver to get the bullion value of the coin. At the time of this writing, silver was $16 an ounce, making a 1964 Kennedy Half Dollar worth about $5.80
U.S. half dollars minted in 1965 through 1970 weigh 11.5 grams and contain 40% silver.
Presently there is no silver in the US half dollar. Until 1964 dimes, quarters and half dollars (and earlier dollars) contained 900/1000 (.900) Silver. In 1964 there were 11.25 grams of silver in a half dollar which is about 0.3620 troy ounces of silver. (Note that a troy ounce used for precious metals is about 31.1034 grams whereas a avoirdupois ounce is about 28.4 grams and a troy pound is 12 troy ounces rather than 16). After 1964 silver was removed from dimes and quarters (except special sets of quarters) and in the half dollar the silver was reduced to 4.60 grams (1965-1970). This was known as "clad" halves because the outside was .800 silver and the inside .210. After 1970 silver was removed from all regular issue US coinage. There was also a clad special issue of the 1776-1976 bicentennial half. Sterling silver is .925 and pure is considered at least .999.Presently there is no silver in the US half dollar. Until 1964 dimes, quarters and half dollars (and earlier dollars) contained 900/1000 (.900) Silver. In 1964 there were 11.25 grams of silver in a half dollar which is about 0.3620 troy ounces of silver. (Note that a troy ounce used for precious metals is about 31.1034 grams whereas a avoirdupois ounce is about 28.4 grams and a troy pound is 12 troy ounces rather than 16). After 1964 silver was removed from dimes and quarters (except special sets of quarters) and in the half dollar the silver was reduced to 4.60 grams (1965-1970). This was known as "clad" halves because the outside was .800 silver and the inside .210. After 1970 silver was removed from all regular issue US coinage. There was also a clad special issue of the 1776-1976 bicentennial half. Sterling silver is .925 and pure is considered at least .999.Three pre-1965 halves equal 1.08600 troy ouncesEli58
Before 1970, half dollars had silver in them, but in 1970, they used no silver in the coins, so it is worth only $0.50.
U.S. half dollars minted in 1965 through 1970 weigh 11.5 grams and contain 40% silver.
No half dollars intended for circulation minted since 1970 contain any silver. No 1972 half dollar has any silver. It is only worth 50 cents.