Answer : The time required for decay is, 84 days.
Explanation :
Half-life of chromium-51 = 28 days
First we have to calculate the rate constant, we use the formula :



Now we have to calculate the time required for decay.
Expression for rate law for first order kinetics is given by:

where,
k = rate constant
t = time taken by sample = ?
a = let initial activity of the sample = 100
a - x = amount left after decay process = 12.5
Now put all the given values in above equation, we get


Therefore, the time required for decay is, 84 days.
The specific heat capacity is intensive, and does not depend on the quantity.
We can categorize a property of the compound as either intensive or extensive when defining a particular aspect of it. The extent of a drug or compound is a quality that is influenced by the sample size used. However, the intense property is independent of the quantity (we can say that it is independent on the amount of the sample used). One such example of an intensive property is density.
The specific heat capacity of a substance or a compound describes the amount of heat (in Joules) needed to increase the temperature of one gram of the substance by 1 unit.
The specific heat capacity is independent on the amount of substance used, therefore, it is classified as an intensive property of a substance. The specific heat capacity will not depend on the mass of the given substance and it will be a constant value for each substance.
So the specific heat capacity is intensive, and does not depend on the quantity, but the heat capacity is extensive, so two grams of liquid water have twice the heat capacitance of 1 gram, but the specific heat capacity, the heat capacity per gram, is the same, 4.184 (J/g.K).
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Thermal Energy, Electrical Energy, Light, Sound, Nuclear Energy, and Chemical Energy
The speed of sound depends on these two things: The type of medium and the temperature of the medium; option a.
<h3>What is the speed of sound?</h3>
The speed of sound is the distance covered in meters over a given period of time.
Speed = distance/time
The speed of sound depends on the following:
- temperature - the speed of sound increases with temperature
- medium - the speed of sound increases with increase in density of the medium.
In conclusion, the speed of sound increases with temperature.
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The activation energy barrier is 40.1 kJ·mol⁻¹
Use the Arrhenius equation





