Explanation:
1) Initial mass of the Cesium-137== 180 mg
Mass of Cesium after time t = N
Formula used :
Half life of the cesium-137 = = initial mass of isotope
N = mass of the parent isotope left after the time, (t)
= half life of the isotope
= rate constant
Now put all the given values in this formula, we get
Mass that remains after t years.
Therefore, the parent isotope remain after one half life will be, 100 grams.
2)
t = 70 years
N = 35.73 mg
35.73 mg of cesium-137 will remain after 70 years.
3)
N = 1 mg
t = ?
t = 224.80 years ≈ 225 years
After 225 years only 1 mg of cesium-137 will remain.
Answer:
The basic essential activities performed by an organism to withstand its life are called as life processes. These include nutrition, respiration, circulation, excretion and reproduction. Organisms obtain energy from food to perform these life processes which are essential for survival.
I. Because they're a limited resource
2 Because they're a cause of carbon pollution.
Explanation:
Relation between pressure, latent heat of fusion, and change in volume is as follows.
Also,
where, is the difference in specific volumes.
Hence,
As, = 22.0 J/mol K
And, ...... (1)
where, = density of water
= density of ice
M = molar mass of water =
Therefore, using formula in equation (1) we will calculate the volume of fusion as follows.
=
=
Therefore, calculate the required pressure as follows.
=
or, = 145 bar/K
Hence, for change of 1 degree pressure the decrease is 145 bar and for 4.7 degree change dP =
= 681.5 bar
Thus, we can conclude that pressure should be increased by 681.5 bar to cause 4.7 degree change in melting point.
Answer:
P₂ = 2.7 atm
Explanation:
Given data:
Initial temperature = 30°C
Initial pressure = 3.00 atm
Final temperature = -5°C
Final pressure = ?
Solution:
Initial temperature = 30°C = 30 + 273 = 303 K
Final temperature = -5°C = -5 + 273 = 268 K
According to Gay-Lussac Law,
The pressure of given amount of a gas is directly proportional to its temperature at constant volume and number of moles.
Mathematical relationship:
P₁/T₁ = P₂/T₂
Now we will put the values in formula:
3.0 atm / 303 K = P₂/268 K
P₂ = 3.0 atm × 268 K / 303 K
P₂ = 804 atm. K /293 K
P₂ = 2.7 atm