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navik [9.2K]
3 years ago
13

The half-life of radium-226 is 1590 years. if a sample contains 100 mg, how many mg will remain after 1000 years?

Chemistry
1 answer:
Katyanochek1 [597]3 years ago
4 0

Answer:

a=64.7mg

Explanation:

Hello,

In this case, we need to remember that for the required time for a radioactive nuclide as radium-226 to decrease to one half its initial amount we are talking about its half-life. Furthermore, the amount of remaining radioactive material as a function of the half-lives is computed as follows:

a=a_0(\frac{1}{2} )^{\frac{t}{t_{1/2}} }

Therefore, for an initial amount of 100 mg with a half-life of 1590 years, after 1000 years, we have:

a=100mg(\frac{1}{2} )^{\frac{1000years}{1590years} }\\\\a=64.7mg

Best regards.

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86.14 mL of an acid solution was needed to neutralize 30.24 mL of a base solution of unknown concentrations. A second trial is r
Airida [17]

Answer:

The correct answer is option B.

Explanation:

As given ,that 30.24 mL of base was neutralize by 86.14 mL of acid which means that moles of base present in 30.24 mL are neutralized by moles of acid present in 86.14 mL.

After dilution of base from 30.24 mL to 50.0 mL .Since, the moles of base are same in the solution as that of the moles in solution before dilution. Moles of acid require to neutralize the base after dilution will same as a that of present moles of acid present in 86.14 mL.

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3 years ago
What happens to an electron when it emits a photon
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Answer:

when electron emit the radiations it means it jumped to the lower energy level from higher energy level.

Explanation:

When electron jump into lower energy level from high energy level it loses the energy.

The process is called de-excitation.

Excitation:

When the energy is provided to the atom the electrons by absorbing the energy jump to the higher energy levels. This process is called excitation. The amount of energy absorbed by the electron is exactly equal to the energy difference of orbits.

De-excitation:

When the excited electron fall back to the lower energy levels the energy is released in the form of radiations. this energy is exactly equal to the energy difference between the orbits. The characteristics bright colors are due to the these emitted radiations. These emitted radiations can be seen if they are fall in the visible region of spectrum.

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