Answer:
Ferric oxide reacts with aluminium to produce aluminium oxide and iron. The balanced chemical equation for the given reaction is : Fe2O3 + 2Al → Al2O3 + 2Fe.
Concave is not a type of mechanical wave because it doesn’t need a medium for propagation.
Answer:


Explanation:
Given



Required
Determine the area
The area of a triangle is :

By substituting values for the x and y coordinates of A, B and C;
We have:

So:
For instance



The area is:






Hydrogen has only one electron. It has one proton of nucleus and one outter electron.