The formula for density is D=m/v, where m=mass and v=volume. So we can just do 890/100 and we end up with 8.90. The density of the copper is 8.90 grams per cm3
:)
The average atomic mass of Neon would simply be the sum of the weighted average of each isotope. That is:
average atomic mass = 0.905 * 20 + 0.003 * 21 + 0.092 * 22
average atomic mass = 20.187 amu
Answer:
Chemical reactivity increases down a group and decreases from left to right of a period.
Explanation:
The higher the ionization energy is, the lower the reactivity is. Since the ionization energy is highest in the top right corner of the periodic table, we can assume that the most reactive elements are in the opposite bottom left corner. This is because the electrons that react are farther away from the nucleus thus experience less attraction to the nucleus (called nuclear shielding). Therefore their electrons are more easily removed than elements that don't ecperience nuclear shielding.