If by Period you mean Column, they share the same amount of electrons in their outer shell.
Answer:
Where is the picture? Can't answer without it.
<span>You can separate mixtures that have magnetic components. The reason is because you can use magnetism to separate out the magnetic components.</span>
All colors but red is being absorbed by the material.
<h3>
Answer:</h3>
482.596 grams
<h3>
Explanation:</h3>
The relationship between moles, molar mass and mass of a compound is given by;

In this case;
The compound in question is P₂O₅
Molar mass of P₂O₅ = 141.94 g/mol
Rearranging the formula;
Mass = Moles × molar mass
Therefore;
Mass of P₂O₅ = 3.4 mol × 141.94 g/mol
= 482.596 grams
Therefore, mass of P₂O₅ is 482.596 grams