Answer:
4 grams
Explanation:
A = A₀e^⁻kt
A₀ = 125.0 grams
k= 0.693/t(1/2) = (0.693/68.8) yrs⁻¹ = 0.01 yrs⁻¹
t = 344.0 years
A = 125.0g·[e^-(0.01yrs⁻¹)(344.0yrs)] = 125(0.032)grams = 4.000g (4 sog. figs. based on A₀ = 125.0 grams)
Answer:
A) 
Explanation:
m = Mass of water = 38.9
M = Molar mass of water = 18 g/mol
= Avogadro's number = 
The reaction of electrolysis would be

Number of moles of 

From the reaction it can be seen that 2 moles of
gives 1 mole of 
So, number of moles of
produced is

Number of molecules

So,
of oxygen is produced.
Given which are missing in your question:
the flask is filled with 1.45 g of argon at 25 C°
So according to this formula (Partial pressure):
PV= nRT
first, we need n, and we can get by substitution by:
n = 1.45/mass weight of argon
= 1.45 / 39.948 = 0.0363 mol of Ar
we have R constant = 0.0821
and T in kelvin = 25 + 273 = 298
and V = 1 L
∴ P * 1 = 0.0363* 0.0821 * 298 = 0.888 atm
Answer choice C. Reduction has its electrons as a reactant.