The half-life of an element is 200 years. if a 30 gram sample was originally deposited, how much is left after 200 years? a. 10 grams b. 15 grams c. 30 grams d. 60 grams one more question if u i will give 100 points

Half lives can be a bit confusing. Half lives are what how long it takes for half of a sample of a radioactive element to decay. So If there is 30 grams at the start, and the half life is 200 years, after 200 years, half of it is decayed, and 30÷2=15, so there will be 15 grams left. Answer choice B

Wow you’re learning half life in middle school?? But anyways, half life is the time taken for the amount of reactants to become half of its initial value. so 30g becomes 15g after 1 half life = 200 years

Ifound this on google “laws of chemical combination. it states that matter can neither be created nor destroyed. it stated that a given compound always contains exactly the same proportion of elements by weight.” i hope this you for what your looking for.