1 mole = 6.22 x 10^23 molecules (Avogadro's number)
15 moles x (6.22 x 10^23) = 9.33 x 10^24 atoms
The symbol, the atomic mass, the number of protons and electrons
Answer:
In the criss-cross method, the numerical value of the ion charge of the two atoms are crossed over, which becomes the subscript of the other ion. Using this technique, we will write the chemical formula of the given compounds.
Criss cross the absolute values to give Al2O3. To find the formula for magnesium oxide:- The oxidation number of Mg is +2 and oxygen is -2. Criss cross the absolute values to give Mg2O2In this example there is a common factor of 2 so divide by 2 to give MgO.
Group 1 elements (usually called alkali metals) are not very electronegative and have small ionization energies due to that. The reason why they are not very electronegative is that they really want to loose their one valence electron so that they can have a noble gas electron configuration (completed octet).
I hope this helps.