Answer: Antoine Lavoisier.
He classified the elements into four groups: elastic fluids, nonmetals, metals and earths. Some of the called elementes were not really elements (light and heat). Others were compounds, e.g. hydrochloric acid.
Answer: Option (C) is the correct answer.
Explanation:
An ion is defined as a specie which is formed when a neutral atoms tends to gain or lose an electron.
When a neutral atom gain an electron then it forms a negative ion whereas when a neutral atom tends to lose an electron then it forms a positive ion.
For example, a neutral fluorine atom on gaining an electron will form 
ion. And, a sodium atom on losing an electron forms 
ion.
When a group of atoms form ions then it tends to form polyatomic ions.
Thus, we can conclude that group of atoms that gains or loses electrons is called a polyatomic ion.
Answer:
Protons
Explanation:
It's the number of protons in the nucleus of an atom, which determines the chemical properties of an element and its place in the periodic table.
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<h3><u>Answer;</u></h3>
The value of Kc does not depend on starting concentrations.
<h3><u>Explanation;</u></h3>
- <em><u>At constant temperature, changing the equilibrium concentration does not affect the equilibrium constant, because the rate constants are not affected by the concentration changes. </u></em>
- When the concentration of one of the participants is changed, the concentration of the others vary in such a way as to maintain a constant value for the equilibrium constant.
Answer:
The total number of atoms is 12 + 22 + 11 = 45, so carbon atoms are 12/45 of the total.
Explanation:
