The much of the sample that would remain unchanged after 140 seconds is 2.813 g
Explanation
Half life is time taken for the quantity to reduce to half its original value.
if the half life for Scandium is 35 sec, then the number of half life in 140 seconds
=140 sec/ 35 s = 4 half life
Therefore 45 g after first half life = 45 x1/2 =22.5 g
22.5 g after second half life = 22.5 x 1/2 =11.25 g
11.25 g after third half life = 11.25 x 1/2 = 5.625 g
5.625 after fourth half life = 5.625 x 1/2 = 2.813
therefore 2.813 g of Scandium 47 remains unchanged.
Hello.
The answer is C.Amine
When an amine is combined (reacted) with a carboxyl group, an AMIDE + water is formed, and if you carry on heating under a vacuum, an imidazoline is formed.
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Answer: I don't know if this helps you or not, but this is from study.com:
I'm so sorry if it doesn't:
Explanation: Iron(III) oxide reacts with carbon monoxide according to the balanced equation:
Fe₂O₃ + 3CO ➡️ 2Fe + 3CO₂
A reaction mixture initially contains 23.00g Fe₂O₃ and 15.40g CO.
<span>When two or more substances are mixed together but not chemically joined they are called as mixtures. Therefore, it is only a physical change taking place.
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I hope this helps you! Good luck :)
First one I believe is 5.
2nd is given already
3rd is 1
4th is 2