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elena-14-01-66 [18.8K]
2 years ago
14

The half-life of 131I is 80 days. How much of a 500.0 mg sample remains after 3 half lives?

Chemistry
1 answer:
I am Lyosha [343]2 years ago
6 0

Answer:

62.5 mg

Explanation:

Just multiply the original amount by  1/2   three times:

500 mg  x  1/2  x  1/2  x  1/2 = 62.5 mg

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Diatomic O2 can react with the element magnesium to form magnesium oxide (MgO). The balanced chemical equation is: 2Mg + O2 → 2M
tigry1 [53]

Answer:

We will expect 4 moles of MgO to be formed (option b).

Explanation:

Step 1: The balanced equation

2Mg + O2 → 2MgO

Step 2: Data given

Number of moles of Magnesium = 4 moles

Oxygen = in excess  → this means Magnesium is the limiting reactant

Magnesium will completely be consumed ( 4 moles). There will remain 0 moles.

For 2 moles of magnesium consumed, we need 1 mole of oxygen to produce 2 moles of MgO.

For 4 moles of magnesium, we need 4/2 = 2 moles of oxygen.

For 4  moles of magnesium, we will produce 4/1 = 4 moles of MgO

We will expect 4 moles of MgO to be formed (option b).

4 0
3 years ago
Solid iron metal reacts with solid sulfur at room temperature to produce solid iron (ll) sulfide? Express as a chemical equation
kupik [55]
Answer:Fe+S=FeS

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5 0
2 years ago
Check my answer plz!! 100 points. Tell me if they are wrong! 1. You have three elements, A, B, and C, with the following electro
Artyom0805 [142]

look good w small changes below:

Answer:  


AB is an ionic compound. The electronegativity difference between A and B is greater.  


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6 0
3 years ago
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Can someone please check my answer??!!!
Ksenya-84 [330]

Answer:

I think its correct

5 0
3 years ago
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N2 + 6e → 2N-3
sveta [45]

Answer:

The correct answer is reduction.

Explanation:

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3 years ago
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