Answer:
C
Explanation:
Wind is geological therefore it is geological weathering
After 25 days, it remains radon 5.9x10^5 atoms.
Half-life is the time required for a quantity (in this example number of radioactive radon) to reduce to half its initial value.
N(Ra) = 5.7×10^7; initial number of radon atoms
t1/2(Ra) = 3.8 days; the half-life of the radon is 3.8 days
n = 25 days / 3.8 days
n = 6.58; number of half-lifes of radon
N1(Ra) = N(Ra) x (1/2)^n
N1(Ra) = 5.7×10^7 x (1/2)^6.58
N1(Ra) = 5.9x10^5; number of radon atoms after 25 days
The half-life is independent of initial concentration (size of the sample).
More about half-life: brainly.com/question/1160651
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Answer:
1.53 atm
Explanation:
From the question given above, the following data were obtained:
Volume = constant
Initial pressure (P₁) = stp = 1 atm
Initial temperature (T₁) = 273 K
Final temperature (T₂) = 144 °C = 144 °C + 273 = 417 K
Final pressure (P₂) =?
Since the volume is constant, the final pressure can be obtained as follow:
P₁ / T₁ = P₂ / T₂
1 / 273 = P₂ / 417
Cross multiply
273 × P₂ = 417
Divide both side by 273
P₂ = 417 / 273
P₂ = 1.53 atm
Therefore, the final pressure (i.e the pressure inside the hot water bottle) is 1.53 atm.
Phosphoric acid is a weak acid, while rubidium hydroxide is a strong acid.
H₃PO₄ + RbOH --> Rb₃PO₄ + H₂O
We get Rb₃PO₄ because PO₄ has a charge of 3-, that is PO₄³⁻. Rb has a charge of 1+. You give the subscript of one the charge of the other as this is an ionic compound. So you end up with Rb₃PO₄, a neutral compound.
Now let's balance the equation:
H₃PO₄ + 3RbOH --> Rb₃PO₄ + 3H₂O