Answer:
Two Half-lives
Explanation:
Let number of Parent nuclei Initially present be X,
Then, finally 
Parent nuclei Will remain with 
daughter nuclei.
In one half- life , parent nuclei becomes half of initial.
So, starting with X parent nuclei,
After one half-life, it will degrade to 
.
After another half life , Parent nuclei will become half of
Which is equal to .
So, Parent nuclei have to go through Two half-lives.
The answer is a. a homogenous mixture
I think it’s 7.41 because you count up all the atoms and find out how many are x (the large grey ones) and you do 2/27 x 100 which gives you 7.41 :) (sorry if i counted wrong it’s kinda hard)
We know that, M1V1 = M2V2
(Initial) (Final)
where, M1 and M2 are initial and final concentration of soution respectively.
V1 and V2 = initial and final volume of solution respectively
Given: M1 = 12 m, V1 = 35 ml and V2 = 1.2 l = 1200 ml
∴ M2 = M1V1/V2 = (12 × 35)/ 1200 = 0.35 m
Final concentration of solution is 0.35 m
Answer: Proton will have larger wavelength
Explanation:
(de-Broglie's equation)
h= Planck constant
m= mass of the particle
v= velocity of the particle
As we can see from the de-Broglie's equation , that wavelength is inversely proportional to the product of mass into velocity of the object.
The wavelength of proton will be higher than that fast moving golf ball because mass of proton 
is very small than that of the golf ball (45.93 g). Proton is moving at slow velocity and the golf ball is moving with fast velocity by which value of product of mass into velocity of proton will be lower than the value of product of mass into velocity of the golf ball which will result in larger value of wavelength of the proton.
