Answer:
15 h
Explanation:
Okay, the first thing that we all have to know before we can answer this question is that this Topic that is, Chemistry of Radioactivity is related to kinetics in a way that Radioactive disintegration follows the first order of Reaction which is under kinetics. So, we will be using the first order kinetics rate law to answer this question. Using the equation (1) below;
k =[ 2.303/ t ]×log ([N°}/ [Nr]) --------(1).
We are given from the question that N° = initial sample = 0.8 mg and Nr= sample remaining = 0.2 and the time taken = t= 30.0 h.
k= (2.303/ 30.0 h ) × log (0.8/0.2).
k=0.076768 h^-1 × log (4).
k= 0.076768 h^-1 × 0.6021.
k= 0.0462 h^-1.
Therefore, using the formula for Calculating half life below for first order kinetics we will be able to find out answer.
k = ln 2/ t(1/2). Where t(1/2) is the half life.
t(1/2) = ln 2/ k.
t(1/2) = ln 2 / 0.0462 h^-1.
t(1/2)= 0.6931/0.0462 h^-1.
t(1/2)=15 h
Hey there!
density = 2.67 g/cm³
mass = 1340 g
volume = ?
Therefore:
D = m / V
2.67 = 1340 / V
V = 1340 / 2.67
V = 501.87 cm³
Answer:
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Explanation:
Answer : The mass of liquid sodium needed are, 
Explanation :
First we have to calculate the number of moles of liquid sodium.
where,
q = heat absorb = 1.20 MJ = 1.20 × 10⁶ J
n = number of moles of liquid sodium = ?
c = specific heat capacity = 
= change in temperature = 
Now put all the given values in the above formula, we get:
Now we have to calculate the mass of liquid sodium.
Molar mass of Na = 23 g/mol
Therefore, the mass of liquid sodium needed are,
The nuclear equation :
₈₂²¹⁴Pb ⇒ ₈₃²¹⁴Bi + ₋₁⁰e
<h3>Further explanation
</h3>
Given
₈₂²¹⁴Pb
beta β ₋₁e⁰ particles
Required
Nuclear equation
Solution
Radioactivity is the process of unstable isotopes to stable isotopes by decay, by emitting certain particles,
-
alpha α particles ₂He⁴
- beta β ₋₁e⁰ particles
- gamma particles ₀γ⁰
- positron particles ₁e⁰
- neutron ₀n¹
The principle used is the sum of the atomic number and mass number before and after the decay reaction is the same
The reaction
₈₂²¹⁴Pb ⇒ X + ₋₁⁰e
The element X has
-the atomic number = 82 + 1 = 83
-the mass number = 214
In the periodic system, the element with atomic number 83=Bismuth
