Answer:
A
Explanation:
lies to the left of periodic table
It would be Magnesium = 1 atom, Oxygen = 2 atoms, Hydrogen = 2 atoms. It has 5 atoms total. There is 1 magnesium and you multiply each element by the the 2 outside the parenthesis to get 2 oxygen and 2 hydrogen.
Hi!
To make 500 mL of a 1,500 M solution of NaCl you'll require
43,83 g
To calculate that, you will need to use a conversion factor to go from the volume of the 1,500 M solution to the required grams. For this conversion factor, you'll use the definition for Molar concentration (M=mol/L) and the molar mass of NaCl. The conversion factor is shown below:

Have a nice day!
Answer:
Isotope, one of two or more species of atoms of a chemical element with the same atomic number and position in the periodic table and nearly identical chemical behaviour but with different atomic masses and physical properties.