Mass can’t be destroyed. So since not all the mass was found in the products, that simply means that it was lost to the environment. For example, let’s say hydrogen and oxygen are the reactants and we get water in the product. Now that oxygen could have reacted with something else that we didn’t take into account when measuring the mass of the H2O released.
Tldr, some of the reactants were lost to the surroundings
Valence Electron is the outermost electrons, family(Alkali) 1 has 1 valence electrons and family(Alkaline) 2 has 2 valence electrons.
Hope this helps
There are several information's already given in the question. Based on the information's provided, the answer can be easily deduced.
V1 = 25 ml
= 25/1000 liter
= 0.025 liter
V2 = 18 ml
= 18/1000 liter
= 0.018 liter
M2 = 1.0 M
M1 = ?
Then
M1V1 = M2V2
M1 = M2V2/V1
= (1 * 0.018)/0.025
= 0.72 M
From the above deduction, it can be easily concluded that the correct option among all the options that are given in the question is the first option or option "A". I hope that this is the answer that has actually come to your help.
Bronsted lowry bases
NO2- amd OH-