1) Which of the following is a possible formula unit? PbO - Li2B - Al2Pb3 - ClO
The correct answer is PbO which is Lead(II) oxide – also known as Lead Monoxide – which is an inorganic compound. It is an Amphoteric oxide which can be found, in modern use, in industrial glass, ceramics, or computer components, due to its crystal structure.
2) What is the formula of a compound formed between iodine (I) and calcium (Ca)?
Calcium will always give two electrons. but iodine can receive only one. Therefore two atoms of iodine react with one atom of calcium to give CaI2. Their bond is an ionic bond.
Ca 2+ + 2I 1- --> CaI2
3) What is the resulting formula unit when strontium (Sr) and phosphorus (P) bond?
Strontium (Sr) wants to lose two (2) electrons, and phosphorus (P) wants to gain three (3). By using the criss-cross method, if you flip the 2 and 3 to the opposite elements, you will end up with the formula Sr3P2.