0.69moles
Explanation:
Given parameters:
Number of atoms = 4.14 x 10²³atoms
Atom = Na
Unknown:
Number of moles of Na atom in it = ?
Solution:
A mole of a substance is the quantity of substance that contains the avogadro's number of particles.
1 mole = 6.02 x 10²³particles
To solve this problem, simply use the expression below;
Number of moles = 
Input the parameters;
Number of moles =
= 0.69moles
learn more;
Number of moles brainly.com/question/1841136
#learnwithBrainly
Holds the particles tightly
Answer:
Therefore it takes 8.0 mins for it to decrease to 0.085 M
Explanation:
First order reaction: The rate of reaction is proportional to the concentration of reactant of power one is called first order reaction.
A→ product
Let the concentration of A = [A]
![\textrm{rate of reaction}=-\frac{d[A]}{dt} =k[A]](https://tex.z-dn.net/?f=%5Ctextrm%7Brate%20of%20reaction%7D%3D-%5Cfrac%7Bd%5BA%5D%7D%7Bdt%7D%20%3Dk%5BA%5D)
![k=\frac{2.303}{t} log\frac{[A_0]}{[A]}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B2.303%7D%7Bt%7D%20log%5Cfrac%7B%5BA_0%5D%7D%7B%5BA%5D%7D)
[A₀] = initial concentration
[A]= final concentration
t= time
k= rate constant
Half life: Half life is time to reduce the concentration of reactant of its half.

Here 


To find the time takes for it to decrease to 0.085 we use the below equation
![k=\frac{2.303}{t} log\frac{[A_0]}{[A]}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B2.303%7D%7Bt%7D%20log%5Cfrac%7B%5BA_0%5D%7D%7B%5BA%5D%7D)
![\Rightarrow t=\frac{2.303}{k} log\frac{[A_0]}{[A]}](https://tex.z-dn.net/?f=%5CRightarrow%20t%3D%5Cfrac%7B2.303%7D%7Bk%7D%20log%5Cfrac%7B%5BA_0%5D%7D%7B%5BA%5D%7D)
Here ,
, [A₀] = 0.13 m and [ A] = 0.085 M


Therefore it takes 8.0 mins for it to decrease to 0.085 M