Answer:
Explanation:
a )
m = m₀ 
m is mass after time t . original mass is m₀ , λ is disintegration constant
λ = .693 / half life
= .693 / 1590
= .0004358
m = m₀ 
b )
m = 50 x 
= 40.21 mg .
c )
40 = 50 
.8 =
= 1.25
.0004358 t = .22314
t = 512 years .
Answer:
The molarity of a solution is 2.5 M
Explanation:
Molarity is a concentration unit that describes how much of a solution is dissolved in solution.
Molarity of a solution can found by using the formula,
Molarity (M) = (moles of solute)/(Liters of Solution).
Given, mass of Sodium = 114.95 grams.
Volume of water = 2 L.
Here, Sodium is solute as it is dissolved in water, which is the solvent.
Moles of Sodium(solute) can be found by using the formula,
Number of Moles = mass/Molecular weight.
mass of Sodium = 114.95 grams.
Molecular weight = 22.989 grams
Number of Moles of Sodium(solute) =114.95/22.989 = 5.
Substituting the values in the formula, we get,
M = 5/2 = 2.5 M
Answer:
11. A)outward
12. B) inward
13. B) opaque
14. I really don't know (sorry)
Explanation:
Answer:
1. not affected by a magnet 1 liquid
2. mostly space 2 solid
3. flows freely but particles still attract 3 proton
4. positively charged particles 4 gas
5. free to move in all space 5 alpha particles
6. negatively charged particles 6 atoms
7. atoms nearly fixed in space 7 gamma ray 8. helium nucleus 8 electron (beta)
