Parantheses mean present of a subgroup or a group of polyatomic ions in a chemical reaction.
<u>Explanation:</u>
In a chemical reaction, sometimes, a compound may be composed of group of polyatomic ions with other ions. Some of the polyatomic ions are sulfate, carbonate, nitrate, hydroxide, bicarbonate, ammonia etc.
So these polyatomic ions are formed by combining two or more elements. Thus, if the number of polyatomic ions in a compound is more than one, then we use parathesis and write those polyatomic ions in it and write the number of polyatomic ions present in the compound as subscript of the parathesis.
For example, Fe₂(SO₄)₃
So here SO₄ is a polyatomic ion and in the compound 3 atoms of SO₄ is required to neutralize the compound and thus paranthesis is used. Thus, parantheses mean present of a subgroup or a group of polyatomic ions in a chemical reaction.
Here's the numbers
H = +1
Cl = -1
Mass
Explanation:
Mass is different from the rest based on those two categories.
Physical properties are the properties of matter that are usually determined with our senses like taste, feel, color, odor e.t.c
Chemical properties are the properties that relates to a substance when changes are occurring to it.
These properties are boiling point, magnetism and thermal conductivity among others.
Mass is not a physical nor chemical property. It is classified as an extensive property of substances which varies according to the amount of matter it contains.
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The definition of the age or date of organic matter from the relative proportions of the carbon isotopes carbon 12 and carbon 14 that it contains.