The bracket just separate an atom or the ion and in the above it means there are two hydroxide molecules
so bracket function is just to separate ions and molecules
hope it helps
Answer:
Proton is a sub atomic particle while oxygen is an atom ....
Of the following, which is most likely to result after a farmer sprays his crops with pesticides?D. A neighbor’s well tests positive for pesticides.
Carbon dioxide is a colorless, odorless gas. Why is it considered a pollutant?
A. It gets into natural waters and kills fish.
Answer : The number of moles of argon gas is, 11.5 mol
Explanation :
To calculate the moles of argon we are using ideal gas equation as:

where,
P = pressure of argon gas = 658 mmHg = 0.866 atm (1 atm = 760 mmHg)
V = volume of argon gas = 30.6 L
n = number of moles of argon gas = ?
R = gas constant = 0.0821 L.atm/mol.K
T = temperature of argon gas = 28 K
Now put all the given values in the above formula, we get:


Therefore, the number of moles of argon gas is, 11.5 mol