Answer:
By criss crossing the charge numbers we find the chemical formula of a compound
For example Aluminium chloride
Al has [tex]3^+[/tex] charge and Cl has [tex]1^-[/tex] charge
3 becomes the subscript of Cl and 1 becomes the subscript of Al
So the chemical formula will be [tex]Al_1 Cl_3[/tex]
Ionic compounds are named using format as follows
Metal’s name + root word of the non metal + ide ending (when the metal has only one type of charge)
Example NaCl is named as Sodium + chlor + ide = Sodium chloride
Metal’s name + charge in roman numeral + root word of non metal + ide ending (when the metal possess more than one type of charge)
Example
[tex]FeCl_2[/tex] is named as Iron+(II)+chlor+ide =Iron(II)chloride
[tex]FeCl_3[/tex] is named as Iron+(III)+chlor+ide =Iron(III)chloride
From the formula CuO we get to know the charge numbers of Cu is [tex]2^+[/tex] and O is [tex]2^-[/tex]
CuO is Copper (II) oxide
Metal + roman numeral for charge + root word of non metal + ide ending used in this
It is an ionic compound since it has a metal and a non metal.
When there is a polyatomic ion present for example [tex]Na_3 PO_4[/tex] the name of the polyatomic ion is used as it is instead of ’ide’ ending
Thus [tex]Na_3 PO_4[/tex] is Sodium phosphate
[tex]Ca(OH)_2[/tex]
Ca possess only one type of charge that is 2+ .So we don’t use roman numeral for the metal.
[tex]OH^-[/tex] is Hydroxide ion and it is a polyatomic ion
So the name of the compound is Calcium hydroxide
