Answer: The element is represented as Aluminium-27
Explanation:
Atomic number is defined as the number of protons or number of electrons that are present in an electrically neutral atom.
Atomic number = Number of electrons = Number of protons = 13
Mass number is defined as the sum of number of protons and neutrons that are present in an atom.
Mass number = Number of protons + Number of neutrons = 13 + 14 = 27
Thus the element with atomic number of 13 is aluminium and its mass number is 27. Thus it is represented as Aluminium-27
Answer:
Coefficient in front of the 
in the balanced equation - 4
Explanation:
The unbalanced reaction is shown below as:-
On the left hand side,
There are 1 nitrogen atom and 3 hydrogen atoms and 3 oxygen atoms
On the right hand side,
There are 1 nitrogen atom and 2 hydrogen atoms and 2 oxygen atoms
Thus,
Right side, 
must be multiplied by 6 and by 4
Left side, 
is multiplied by 5 and 
by 4 so to balance the whole reaction.
Thus, the balanced reaction is:-
<u>Coefficient in front of the in the balanced equation - 4</u>
Answer:
Low melting point.
Explanation:
We cannot link the pH of a substance from it bonds directly.
Ionic compounds have strong ionic bonds but we cannot say that they will have high or low pH.
High conductivity is a feature of ionic compounds generally (also metals)
low melting point means the bonds are weak so they can be weak covalent bonds.
Low flammability is not related to bonding.
