Explanation:
Atoms are the smallest unit of matter that can't be broken down chemically. Molecules are groups of two or more atoms that are chemically bonded. Ions are atoms or molecules that have gained or lost one or more of their valence electrons and therefore have a net positive or negative charge.
<u>Answer:</u> The concentration of solution is 0.342 M
<u>Explanation:</u>
To calculate the molarity of solution, we use the equation:

We are given:
Mass of solute (Sodium chloride) = 15 g
Molar mass of sodium chloride = 58.5 g/mol
Volume of solution = 750 mL
Putting values in above equation, we get:

Hence, the concentration of solution is 0.342 M
Remark
The given thing on the right is a positron. The mass for these subatomic particles is considered to be 0. It's atomic number is 1 which means it is a blood relative of a proton.
So essentially what happens is that X is one space to the left on the periodic table. But let's solve this a little bit more formally.
Solution

y stays the same at 147. It is z that changes.
65 = z + 1 Subtract 1 from both sides.
64 = z
So the chemical with 64 as its position on the periodic table is
Gadolinium and the answer is C
Answer:
= 0.28M
Explanation:
data:
volume = 0.250 L
= 0.250dm^3 ( 1litre = 1dm^3)
moles = 0.70 moles
Solution:
molarity = 
= 0.70 / 0.250
molarity = 0.28 M