Answer:
1)Na2O
let the valency of Na is x
2(x)+(2)=0
2x+2=0
2x=-2
x=-1
2)ZnO
let the valency of Zn is x
x+2=0
x=-2
3)Al2O3
let the valency of Al is x
2(x)+3(2)=0
2x+6=0
2x=-6
x=-3
4)MgO
let the valency of Mg is x
x+2=0
x=-2
Ionic and covalent bonds are both strong intermolecular forces. They are generally both crystalline in structure. But relatively speaking, ionic bonds are much stronger. As a consequence, they have inherent properties of higher boiling points, higher melting points, lower volatility, etc. Also, ionic bonds display conductive properties because they are strong electrolytes. <em>Thus, the answer is 5) higher melting points.</em>
An example of erosion is the Grand Canyon, which was worn away over time by the Colorado river.
BPA, or bisphenol A, is in most plastics and it is toxic to humans because it can bind to the estrogen hormone and greatly alter your body's natural functions from there. It can also bind to your thyroid hormone.
