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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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When corals are stressed by changes in conditions such as temperature, light, or nutrients, they expel the symbiotic algae living in their tissues, causing them to turn completely white. Warmer water temperatures can result in coral bleaching.

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2 years ago
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The end point of a titration was reached after 22 ml of 0.050 m disodium edta titrant was dispensed into a solution containing t
ale4655 [162]
The moles  of disodium edta  used is  calculated  using  the  below  formula


moles =molarity  x  volume in  liters

molarity=0.050m
volume  in  liters = 22/1000=0.022 L

moles  is  therefore=  0.022 x0.050  =1.1  x10^-3  moles  of  disodium  edta


4 0
3 years ago
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If you know the answer I could really use some help rn!
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8 0
3 years ago
5. Hydrogen &amp; oxygen react chemically to form water. How much water
stepladder [879]

39.25 g of water (H₂O)

Explanation:

We have the following chemical reaction:

2 H₂ + O₂ → 2 H₂O

Now we calculate the number of moles of each reactant:

number of moles = mass / molar weight

number of moles of H₂ = 14.8 / 2 = 7.4 moles

number of moles of O₂ = 34.8 / 32 = 1.09 moles

We see from the chemical reaction that 2 moles of H₂ will react with 1 mole of O₂ so 7.4 moles of H₂ will react with 3.7 moles of O₂ but we only have 1.09 moles of O₂ available. The O₂ will be the limiting reactant. Knowing this we devise the following reasoning:

if        1 moles of O₂ produces 2 moles of H₂O

then  1.09 moles of O₂ produces X moles of H₂O

X = (1.09 × 2) / 1 = 2.18 moles of H₂O

mass = number of moles × molar weight

mass of H₂O = 2.18 × 18 = 39.25 g

Learn more about:

limiting reactant

brainly.com/question/7144022

brainly.com/question/6820284

#learnwithBrainly

6 0
3 years ago
Needed help plzzz on this chemistry homework.
mrs_skeptik [129]
Hertz is units for frequency. (waves per second)
wavelength = speed/frequency

if you're given the speed use that to calculate, if not then you can probably assume it's a wave of light and use the speed of light (3x10^8 m/s) to calculate.

wavelength = (3x10^8)/(1.28x10^17)
= 0.000000002 m
= 2.34 nm

5 0
3 years ago
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