The half-life of tc-99 is 6 hours. if starting with 100g of tc-99 what amount would remain after 18 hours? can show your work so i can see how you got the answer

The answer is 12.5 grams of Tc-99.

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You have 3 six-hour cycles in 18h. So it's

First cycle is half of 100 = 50

Second cycle is half of 50 = 25

Third cycle is half of 25 which is 12.5

in theory, limestone is composed principally of the compound calcium carbonate - caco3, but in reality this compound is deposited in conditions involving a number of other compounds as impurities so it ends up being a mixture of many compounds.

hope this : -)

tony (lordcaos066)