Answer:
These are the isotopes of same element. i.e. hydrogen.
Explanation:
Protium and deutrium are the isotopes of hydrogen.
Isotope:
Atoms of same elements can have different atomic mass but same atomic number . These atom of an elements are called isotopes.
Hydrogen consist of three stable isotopes protium, deutrium and tritium.
These three isotopes are represented as H¹₁ , H²₁ and H³₁ respectively.
Protium consist of one proton and one electron while deutrium consist of one proton , one neutron and one electron. The number of neutron and proton is called mass number while number of electron or proton is called atomic number. The number of proton and electron are always same.That's why protium and deutrium have same atomic number but different atomic mass because there is no neutron present in protium that's why its atomic mass is less than by one from deutrium.
Answer:
2.25 M is the final concentration of hydroxide ions ions in the solution after the reaction has gone to completion.
Explanation:
Moles of NaOH = 
Molarity of the nitric acid solution = 0.250 M
Volume of the nitric solution = 0.150 L
Moles of nitric acid = n



According to reaction, 1 mole of nitric acid recats with 1 mole of NaOH, then 0.0375 moles of nitric acid will react with :
of NaOH
Moles of NaOH left unreacted in the solution =
= 0.375 mol - 0.0375 mol = 0.3375 mol

1 mole of sodium hydroxide gives 1 mol of sodium ions and 1 mole of hydroxide ions.
Then 0.3375 moles of NaOH will give :
of hydroxide ion
The molarity of hydroxide ion in solution ;

2.25 M is the final concentration of hydroxide ions ions in the solution after the reaction has gone to completion.
A metal rail rusting in damp weather.