13.4 billion years is 3 times of the half-life, 4.47 billion years. So the Uranium-238 will go through three times of half decay. So the remain percentage will be 50%*50%*50%=12.5%.
Answer:
7.00
Explanation:
When the solutions are mixed, the HCl dissociates to form the ions H+ and Cl-. The ion H+ will react with the NH3 to form NH4+. The stoichiometry for this is 1 mol of HCl to 1 mol of H+ to 1 mol of Cl-, and 1 mol of H+ to 1 mol of NH3 to 1 mol of NH4+.
First, let's find the number of moles of each one of them, multiplying the concentration by the volume:
nH+ = 0.15 M * 25 mL = 3.75 mmol
nNH3 = 0.52 M * 25 mL = 13 mmol
So, all the H+ is consumed, and the neutralization is completed, thus pH will be the pH of the solvent (water), pH = 7.00.
1) Balanced chemical reaction: Cl₂ + 2NaI → 2NaCl + I₂.
Chlorine and iodine are diatomic molecules.
2) Balanced chemical reaction: 2NH₃ → N₂ + 3H₂.
Nitrogen and hydrogen are diatomic molecules.
3) Balanced chemical reaction: 4Na + O₂ → 2Na₂O.
Sodium in compounds has oxidation number +1 and oxygen -2.
It would be MnSO4
The (II) lets you know it’s the form with a 2+ charge and Sulfate has a 2- charge
These will cancel out making it plain MnSO4
If it was manganese (iii) sulfide the answer would be Mn2(SO4)3
