Answer: a) 3.85 days
b) 10.54 days
Explanation:-
Expression for rate law for first order kinetics is given by:

where,
k = rate constant = ?
t = time taken for decomposition = 3 days
a = let initial amount of the reactant = 100 g
a - x = amount left after decay process = 
First we have to calculate the rate constant, we use the formula :
Now put all the given values in above equation, we get


a) Half-life of radon-222:


Thus half-life of radon-222 is 3.85 days.
b) Time taken for the sample to decay to 15% of its original amount:
where,
k = rate constant = 
t = time taken for decomposition = ?
a = let initial amount of the reactant = 100 g
a - x = amount left after decay process = 


Thus it will take 10.54 days for the sample to decay to 15% of its original amount.
Answer:
hey mate
answer is probably voltage as per me
as
Explanation:
Voltage, electric potential difference, electric pressure or electric tension is the difference in electric potential between two points, which is defined as the work needed per unit of charge to move a test charge between the two points
The light can definitely change the mystery material. This can occur through a change in temperature or color (option C).
A material is affected by light mainly if the material absorbs the light. Based on the chart, we know this mystery material can absorb two types of light:
Moreover, this phenomenon can lead to two main changes:
- Change in temperature: Light affects materials by increasing their temperature of these. A common example is the way the temperature of an object increases if it is exposed to sunlight.
- Change in color: Some materials react to light by changing their color.
Based on this, the material can change its color or temperature.
Note: This question is incomplete; here is the missing part:
A. Yes, but the mystery material can change in only one way, such as by getting warm, because all the light that a material absorbs will affect that material in the same way.
B. No. The mystery material can’t change because the light is not a physical thing. Light cannot change physical things like the mystery material.
C. Yes and the mystery material can change in one or two different ways, such as by getting warm and/or changing color, because different types of light can cause different changes to a material when they are absorbed.
D. There is no way to know whether the mystery material will change or not.
Learn more about sunlight in: brainly.com/question/1603783
Answer:
The right solution is "24.39 per sec".
Explanation:
According to the question,
⇒ 

The time will be:
⇒ 



hence,
⇒ 

42.5g
Explanation:
Given parameters:
Mass of N₂= 35g
Unknown:
Mass of NH₃ = ?
Solution:
Equation of the reaction:
N₂ + 3H₂ → 2NH₃
To solve this problem, we work from the known species to the unknown. The known here is the reacting mass of the N₂. From this we can find the number of moles of the N₂.
Number of moles of N₂ = 
molar mass of N₂ = 28g/mol
Number of moles =
= 1.25moles
From the equation of the reaction:
1 mole of N₂ produced 2 moles of NH₃
1.25 moles of N₂ will produce 2 x 1.25 = 2.5moles of NH₃
Mass of NH₃ = Number of moles of NH₃ x molar mass of NH₃
= 2.5 x (14 + 3)
= 42.5g
Learn more:
number of moles brainly.com/question/1841136
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