Answer : The volume of stock solution needed are, 12.5 mL
Explanation :
Formula used :

where,
are the initial molarity and volume of copper (II) chloride.
are the final molarity and volume of stock solution of copper (II) chloride.
We are given:

Putting values in above equation, we get:

Hence, the volume of stock solution needed are, 12.5 mL
Hello!
Elements are made up of atoms, and elements combine to make compounds. Compounds are made up of molecules, and molecules are made up of atoms.
Nitrogen is an element. It could be made up of one or many atoms. A mixture is made up of compounds, so it is not the answer.
Molecules and compounds are made up of different atoms and elements, but nitrogen is not a molecule or a compound.
There is such a thing as a nitrogen atom, though.
Therefore, your answer would be 2) Atom.
I hope this helps!
The CNS {central nervous system}
I would say is b. The answer
That would be C because sickle cells make you very sick and could lead to death and I remember it by thinking sickle has the word sick in it.