Answer:
Density is defined as how tightly or loosely packed a substance is, or to the number of things or people in a certain area.
Given :
Initial mass , a = 150 gm .
Half time ,
.
Final mass , x = 18.75 gm .
To Find :
The time taken to decay 18.75 gm .
Solution :
We know , time taken is given by :

Here , k is a constant given by :

Putting all given value in above equation :
We get :

Therefore , time taken is 6.94 hours .
Hence , this is the required solution .
N₂ + 3H₂ ⇄ 2NH₃ + heat
In the given equilibrium, we notice that the heat is on the right. which means that if the heat requirements don't meet, the reactants on the right will no longer react due to the lack of heat
but because the reactants on the left don't have such weaknesses, they will keep reacting hence producing more and more ammonia until a new equilibrium is reached
where there will be more ammonia and less nitrogen and hydrogen as compared to the equilibrium we had initially
When an electron in an atom absorbed a photon, the energy of the electron changed by 2.94 × 10⁻¹⁹. The frequency of the photon is 4.4 × 10¹⁴ Hertz .
<h3>How to calculate the frequency of photon ?</h3>
To calculate the frequency of photon use the expression
E = hv
where,
E = Energy
h = Planck's Constant
v = frequency (Hz)
Put the value in above formula we get
E = hv
2.94 × 10⁻¹⁹ = 6.6 × 10⁻³⁴ × v
v = 
= 0.44 × 10¹⁵
= 4.4 × 10¹⁴
Thus from the above conclusion we can say that When an electron in an atom absorbed a photon, the energy of the electron changed by 2.94 × 10⁻¹⁹. The frequency of the photon is 4.4 × 10¹⁴ Hertz .
Learn more about the Plank's Constant here: brainly.com/question/27163891
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