<span> A pure substance is a sample of </span>matter<span> with both definite and constant composition with distinct </span>chemical properties<span>. To avoid confusion, in chemistry a pure substance is often referred to as a "chemical substance".</span>
Answer:
A. New atoms are introduced in the molecules of the substance.
Explanation:
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Answer:

Explanation:
A physical change occurs when only the physical properties change. They are generally reversible and no new substances are formed.
However, in a chemical change, the chemical structures and properties change, plus new substances are formed.
Let's analyze each answer choice.
1. Change in state of matter
The state of matter is a physical property, so this is a physical change.
2. Precipitate was formed
A precipitate is a solid formed in a liquid solution. This is a new substance and a chemical change.
3. Unexpected change in odor.
A change in odor is a sign of chemical change.
4. Formation of bubbles
Bubbles signify the formation of gas or a new substance.
So, the best answer choice is <u>A. change in state of matter</u>
Answer: Molarity of
anions in the chemist's solution is 0.0104 M
Explanation:
Molarity : It is defined as the number of moles of solute present per liter of the solution.
Formula used :

where,
n= moles of solute
= volume of solution in ml = 100 ml
Now put all the given values in the formula of molarity, we get

Therefore, the molarity of solution will be 

As 1 mole of
gives 2 moles of 
Thus
moles of
gives =
Thus the molarity of
anions in the chemist's solution is 0.0104 M