Answer:
1. KI
2. AlBr₃
3. CsNO₃
4. Al(CO₃)₃
Step-by-step explanation:
Reference the periodic table to find the element symbols. For polyatomic ions (carbonate and nitrate), you should also be provided with these charts. If not, memorize them.
Write the element symbols and find their charges. For writing the ionic compounds, whether the charge is negative or positive does not matter.
To find the number of atoms for each element, use the charge of its partner. If the charge is 1, you do not need to write it.
Remove any extra brackets.
1. potassium & iodine
potassium (K) 1+
iodine (I) 1-
KI Since the charges are both 1, you do not need to write them.
2. aluminum & bromine
aluminum (Al) 3+
bromine (Br) 1-
AlBr₃
3. cesium & nitrate
cesium (Cs) 1+
nitrate (NO₃) 1-
The charges are both 1, so you do not need to write them.
Cs(NO₃) You can remove these brackets
CsNO₃
4. aluminum & carbonate
aluminum (Al) 3+
carbonate (CO₃) 1-
Al(CO₃)₃ Keep these brackets because you have 3 of the polyatomic ion.