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Umnica [9.8K]
3 years ago
15

A sample of a certain isotope has an initial activity of 40,000 cpm. After 24.8 days, the activity is 2500 cpm. What is the half

life of the isotope?
Chemistry
1 answer:
Hitman42 [59]3 years ago
5 0

Answer:

6.2 days

Explanation:

initial activity = 40,000 cpm

one half-life = 20,000 cpm

two half-lives = 10,000 cpm

three half-lives= 5,000 cpm

four half-lives = 2500 cpm

24.8 days/4 half-lives = 6.2 days/ half-life

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a mixture of emanations from radioactive atoms is passed through electrically charged plates imagination number one is attracted
slava [35]
Hello there!

The nuclear emanations 1, 2 and 3 are called, respectively:

1) Alpha, beta and gamma

Alpha Radiation consists of two protons and two neutrons, as protons are positive particles, they will be attracted to the negatively charged plate.

Beta Radiation 
is composed of a high-energy electron. As electrons are negative particles, they will be attracted to the positively charged plate.  

Gamma Radiation is composed or photons. Photons don't have charge or mass, and they will not be attracted to the charged plates. This kind of radiation is more penetrating than the other two.

Have a nice day!
3 0
3 years ago
what natural resources are used to make a computer? what natural resource am i using to operate a computer?
Svetach [21]

Oil, coal, natural gas, metals, stone and sand are natural resources. Other natural resources are air, sunlight, soil and water. ... Natural resources also are the raw materials for making products that we use everyday from our toothbrush and lunch box to our clothes, cars, televisions, computers and refrigerators.

7 0
4 years ago
How many moles of NH3 can be produced from 15.0 mol of H2 and excess of N2? express your answer numerically in moles
STALIN [3.7K]

Answer:

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3 0
4 years ago
The mass of an iron(II) sulfate crystal is 8.36 g.How many moles of FeSO4 are in the crystal?
Yuki888 [10]

The number of moles present in the FeSO4 are 0.055 mol.

<u>Explanation:</u>

  • The mass of a substance containing the same number  atoms in 12.0 g of 12C is known as mole. One mole of any substance is equal to  6.023 x 10^23. The moles of a substance can be determined by using the formula,

                 Number of moles = mass in grams / molecular mass

Given,

    mass = 8.36 g,

    molecular mass of FeSO4 = 151.908 g / mol

         number of moles = 8.36 / 151.908

                                       = 0.055 mol.

5 0
3 years ago
A sample of an Iron Oxalato complex salt weighting 0.145 grams requires 34.88 mL of 0.015 M KMnO4 to turn the solution a very li
Amanda [17]

Answer:

5.2 ×10^-4 moles

Explanation:

Equation of reaction:

5C2O4^2- + 2MnO4^- +. 6H^+. ----------> 10CO2. +. 8H2O. + 2Mn^2+

From the information provided in the question:

Volume of potassium permanganate= 34.88ml

Concentration of potassium permanganate= 0.015M

Amount potassium permanganate= 0.015 × 34.88/1000= 5.2 ×10^-4 moles

6 0
4 years ago
Read 2 more answers
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