It would take 147 hours for 320 g of the sample to decay to 2.5 grams from the information provided.
Radioactivity refers to the decay of a nucleus leading to the spontaneous emission of radiation. The half life of a radioactive nucleus refers to the time required for the nucleus to decay to half of its initial amount.
Looking at the table, we can see that the initial mass of radioactive material present is 186 grams, within 21 hours, the radioactive substance decayed to half of its initial mass (93 g). Hence, the half life is 21 hours.
Using the formula;
k = 0.693/t1/2
k = 0.693/21 hours = 0.033 hr-1
Using;
N=Noe^-kt
N = mass of radioactive sample at time t
No = mass of radioactive sample initially present
k = decay constant
t = time taken
Substituting values;
2.5/320= e^- 0.033 t
0.0078 = e^- 0.033 t
ln (0.0078) = 0.033 t
t = ln (0.0078)/-0.033
t = 147 hours
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Answer:
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Answer:
The maximum kinetic energy of electron is = 2.93 × 
Joule
Explanation:
We know that total energy
------------ (1)
Here h = plank's constant = 6.62 × 
J s
c = speed of light = 3 × 
= 261 nm = 261 × 
m
Put all these values in equation (1) we get
E = 7.6 × J
We know that
Total energy = Energy to remove an electron + K.E of electron
Energy to remove an electron = 
Energy to remove an electron = 4.67 × J
K.E of electron = Total energy - Energy to remove an electron
K.E of electron = 7.6 × - 4.67 ×
K.E of electron = 2.93 × Joule
Therefore the maximum kinetic energy of electron is = 2.93 × Joule
Answer:the Boundary of an advancing mass of warm air, in particular the leading edge of the warm sector of a low-pressure system.
Explanation:
Dominant allele
Explanation:
An allele whose trait shows up in an organism when the allele is present is called a dominant allele.
An allele whose trait does not show up in an organism when present is called a recessive allele.
- An allele is the two possible forms of gene.
- A gene can be dominant or recessive in nature.
- An allele is a DNA that occupies a particular locus on a chromosome.
- They usually occur in pairs.
- The allele determines hereditary characteristics.
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Genetics brainly.com/question/10607948
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