Answer: 0.125mg americium
Half-lives is a set of duration when a sample will become half of their original mass. In this case, the initial mass is 1mg and the sample is going for 3 times half-lives. Then the calculation would be: 1mg

= 1/8 mg= 0.125mg.
Answer:
oxygen is a present in our atmosphere and mixed with other gases on the surrounding screen plants are also measure source of getting oxygen they take carbon dioxide from making their food by for the cities and give away oxygen in return
Explanation:
most of the earth oxygen comes from tiny Ocean plants are called phytoplaston
Answer:
Here's what I get
Explanation:
1. Names
I. CH₃-CH₂-COOH = 49. propanoic acid
II. CH₃-CH₂-OH = 46. ethanol
III. CH₃-COO-CH₂-CH₂-CH₃ = 47. propyl ethanoate
IV. H-O-CH₂-CH₂-CH₃ = 48. propan-1-ol
V. H-COO-CH₃ = 51. methyl methanoate
VI. CH₃-COOH = 50. ethanoic acid
2. Precursors
52. methyl propionate ⇒ methanol + propanoic acid
53. ethyl methanoate ⇒ ethanol + methanoic acid