Answer:
Therefore it will take 7.66 hours for 80% of the lead decay.
Explanation:
The differential equation for decay is


Integrating both sides
ln A= kt+c₁

[
]
The initial condition is A(0)= A₀,


.........(1)
Given that the
has half life of 3.3 hours.
For half life
putting this in equation (1)

[taking ln both sides,
]

⇒k= - 0.21
Now A₀= 1 gram, 80%=0.8
and A= (1-0.8)A₀ = (0.2×1) gram = 0.2 gram
Now putting the value of k,A and A₀in the equation (1)




⇒ t≈7.66
Therefore it will take 7.66 hours for 80% of the lead decay.
Answer: b.
is positive and
is positive.
Explanation:-
As the temperature of the pack drops, the energy has been absorbed from the pack for dissolution of
in water. Thus as the energy has been absorbed in the reaction, the reaction is endothermic and the change in enthalpy i.e.
is positive.
The entropy is the measure of degree of randomness. The entropy increases when the randomness increases and the entropy decreases when the randomness decreases. When a substance dissolves in water, it dissociate into ions and hence the randomness increases thus the change in entropy i.e.
is positive.
Arenal Volcano: Plate Tectonic Setting. The volcanic arc of Costa Rica, where Arenal is located, is a chain of mountains resulting from the subduction of the Cocos tectonic plate under the Caribbean Plate. Costa Rica is part of the Central American isthmus, which connects the North and South American continents.
Answer : first opinion and also last
Expiation : Note that these last two reactions, and 2H + 2H → 4He + γ, .Nuclear fusion is a reaction in which two nuclei are combined to form a larger nucleus. Nuclear fusion is a reaction in which two nuclei are combined, or fused, to form a larger nucleus. We know that all nuclei have less mass than the sum of the masses of the protons and neutrons that form them. The missing mass times c2 equals the binding energy of the nucleus—the greater the binding energy, the greater the missing mass.
Answer:
I believe that the percussion instruments are the drum and cymbal.
Explanation: