The first one is the answer
isotopes of an atom have different number of neutrons . the number of protons are not different in isotopes of an atom
Answer:
66.2 % of O
Explanation:
Our compound is the lithium nitrite.
LiNO₂
This salt is ionic and can be dissociated: LiNO₂ → Li⁺ + NO₂⁻
We determine the molar mass:
molar mass of Li + 3 . molar mass of N + 6 . molar mass of O
6.94 g/mol + 3. 14 g/mol + 6 . 16 g/mol = 144.94 g/mol
The mass of oxygen contained in 1 mol of lithium nitrite is:
6 . 16 g/mol = 96 g
So the percentage of oxygen present is:
(96 g / 144.94 g) . 100 = 66.2 %
The answer is homogeneous mixture. It is a mixture which has uniform composition and properties all throughout. Mixtures can be separated by physical processes. Mixtures are systems that consist of two or more substances which are mixed but not chemically combined.
False. Pb is lower than Al in the reactivity series. It cannot replace aluminium in AlCl3
