Answer:
Option C. The same number of energy levels.
Explanation:
From the diagram given above, element (i) belong to group 2 while element (ii) belong to group 6.
Also, both element i and ii belong to the same period (i.e period 4). This simply means that both element i and ii have the same number of energy levels.
NOTE: Elements in the same period have the same number of shells of electrons which simply means they have the same energy levels.
Answer:
Coefficient in front of the 
in the balanced equation - 1
Explanation:
The unbalanced Chemical equation is shown below as:-
On the left hand side,
There are 1 boron atom and 3 fluorine atoms and 1 sodium and hydrogen atoms.
On the right hand side,
There are 2 boron atoms and 6 hydrogen atoms and 1 sodium and fluorine atoms.
Thus,
leftside, 
must be multiplied by 2 to balance boron and right side, 
must be multiplied by 6 to balance fluorine. Left side, 
must be multiplied by 6 to balance sodium and hydrogen atoms.
Thus, the balanced reaction is:-
<u>Coefficient in front of the in the balanced equation - 1</u>
Hydrogen + oxygen --> water
59,1g + x = 528g
528g - 59,1 = x
x = 468,9g
<span>(3) amina ........................</span>
