Answer:
The mass of oxygen is 12.10 g.
Explanation:
The decomposition reaction of potassium chlorate is the following:
2KClO₃(s) → 2KCl(s) + 3O₂(g)
We need to find the number of moles of KClO₃:

Where:
m: is the mass = 30.86 g
M: is the molar mass = 122.55 g/mol
Now, we can find the number of moles of O₂ knowing that the ratio between KClO₃ and O₂ is 2:3
Finally, the mass of O₂ is:

Therefore, the mass of oxygen is 12.10 g.
I hope it helps you!
Answer:
The particles of the medium just vibrate in place.
Explanation:
As they vibrate, they pass the energy of the disturbance to the particles next to them, which pass the energy to the particles next to them, and so on. Particles of the medium don't actually travel along with the wave.
Answer:
He used Velocity and Radius.
Explanation:
The uncertainty truths contradicts Bohr's thoughts of electrons.
Answer:
Explanation:
pH= 7 is neutral, pH<7 - acidic solutions,
pH>7 - basic solution.
The more value of pH, the more basic solution is.
So, the solution with pH = 12 is more basic.