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Lady_Fox [76]
3 years ago
5

The half-life of a certain element is 100 days. How many half-lives will it be before only one-fourth of this element remains? 4

Chemistry
2 answers:
Georgia [21]3 years ago
7 0
The answer is 2 half lives, i checked
jolli1 [7]3 years ago
4 0

Answer;

2 half lives

Explanation;

-Half life is the time taken by a radioactive isotope to decay to half of the original amount.

-For example; if the original mass is 100% the time it takes to decay to 50% is the half life.

-Therefore, in our case; for the element to decay from 1 whole to a half of the element, is one half life, then decaying from a half to one-fourth of the element will be another half life, which means there are two half lives for an element to decay to one-fourth of the element.

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Fine particles, ground level ozone, sulfur dioxide, nitrogen dioxide, lead
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How much heat (in kj) is released when 3.600 mol naoh(s) is dissolved in water? (the molar heat of solution of naoh is â445.1 kj
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<span>-1602 kj

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8 0
3 years ago
Read 2 more answers
Which element is reduced in this reaction? 2kmno4 3na2so3 h2o→2mno2 3na2so4 2koh
erik [133]

In a redox chemical reaction, one species gets reduced and another gets oxidized. Manganese element is reduced in this reaction.

<h3>What is oxidized and reduced?</h3>

In a redox reaction, the increase or decrease in the oxidation number and electrons results in the reduction and oxidation of the chemical species. The oxidation and reduction occur simultaneously in a reaction.

The oxidation number of Mn in permanganate ion was +8 on the left side and decreased to +4 on the right side of the equation. Potassium permanganate is an oxidizing agent that has reduced the manganese ion of the permanganate ion.

Therefore, manganese is reduced.

Learn more about reduction and oxidation here:

brainly.com/question/2427143

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3 0
1 year ago
Please help me #6!!!!!!!!
Vesnalui [34]
I believe that the answer is 12 because there is already 3 O molecules and since its in parentheses with 3 outside it that means that there are 3 of those CO molecules meaning that for every 1 CO there will be 3 O’s so 3, four times Is 12
3 0
3 years ago
A 0.0000792 M sample of Compound X in a solvent has an absorbance of 0.341 at 528 nm in a 1.000-cm cuvet. The solvent alone has
natima [27]

Answer:

a) a = 3485 M⁻¹cm⁻¹

b) C = 0,000127 M

Explanation:

Lambert-Beer law says that there is a linear relationship between absorbance and concentration of a chemical substance. The formula is:

A = a×b×C

Where A is absorbance, a is molar absorptivity, b is path length and C is concentration.

a) In the problem Concentration is 0.0000792 M, b is 1,000cm and Absorbance is absorbance of sample-absorbance of blank: 0,341-0,065 = 0,276

Replacing:

0,276 = a×1,000cm×0,0000792M

<em>a = 3485 M⁻¹cm⁻¹</em>

b) As the experiment consist in the same compound in the same solvent, the molar absorptivity will be the same, a = 3485 M⁻¹cm⁻¹, path length will be 1,000cm and absorbance: 0,508-0,065 = 0,443

Replacing:

0,443 = 3485 M⁻¹cm⁻¹×1,000cm×C

<em>C = 0,000127 M </em>

<em></em>

I hope it helps!

8 0
2 years ago
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