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Nuetrik [128]
3 years ago
6

The original amount of radioactive substance is 10 grams. After several years, 2.5 gtams of the substance is remaining. How many

half-lives havr passed since the mass of the subtance was 10 grams?
Chemistry
1 answer:
nirvana33 [79]3 years ago
8 0
10/2=5 (one half life)
5/2=2.5(two half lives)
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How much energy would be released as an electron moved from the n=4 to the n=3 energy level?
Thepotemich [5.8K]

The energy released when electron move from n=4 to n=3 is 0.66 eV

We know that in an atom energy of nth state is

                                     E_n =  -13.6/n^{2}  eV

where n is the energy level

Therefore,

                   E_4 = -13.6/4^{2} \\E_3  = -13.6/3^{2}

Thus, E_4  =   -0.85eV

         E_3  =  -1.51eV

Therefore, total mount of energy released in moving electron from n=4 to n=3 is given by -

                                       E_4 -E_3

                                   =  -0.85 - ( -1.51)

                                   = 0.66eV

To know more about energy released in electron transition

brainly.com/question/8384785

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8 0
1 year ago
There are two beakers that contain the same liquid substance at the same temperature. The larger beaker is 1,000ml and the small
azamat

Answer:

Answer choice B

Explanation:

Since you do not know the volume of the liquid in each beaker, the one in the smaller beaker could have more substance and therefore more thermal energy. If they had the same amount of substance, then the more voluminous one would radiate faster. However, since you do not know this, there is no way to tell. PM me if you have more questions. Hope this helps!

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3 years ago
What is the formula for the ionic compound formed between calcium and sulfur?
zheka24 [161]

Answer:

CaS

Explanation:

calcium is Ca2+ and sulfur is S2- because the charges are equal you only need one of  each atom, so the answer is CaS

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When water freezes and turns into ice, it releases latent heat. Then, the ice that builds up on the plant will insulate it from the colder surrounding air temperatures. Because of this, some growers choose to spray their crop with water before the freeze occurs.

Explanation:

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2 years ago
I am a little confused
Sonbull [250]
The answer is D. I did that and i got it right.
7 0
2 years ago
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