Answer: The ionic formula of compound is 
and the name is cobalt phosphide.
Explanation:
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
Here element Co is having an oxidation state of +3 called as 
cation and phosphprous forms 
anion with oxidation state of -3. Thus they combine and their oxidation states are exchanged and written in simplest whole number ratios to give neutral
The nomenclature of ionic compounds is given by:
1. Positive is written first followed by the oxidation state of metal in roman numerals in square brackets.
2. The negative ion is written next and a suffix is added at the end of the negative ion. The suffix written is '-ide'.
Thus the name of is cobalt phosphide.
The deeper the diver takes the helium balloon, the more it reduces in size. This is due to the pressure of the water column above pressing on the balloon. According to Boyle’s law (P= k*1/V.), as the volume of the balloon decreases, the pressure of the helium inside increases.
Are produced 72 grams of water in this reaction.
<h3>Mole calculation</h3>
To find the value of moles of a product from the number of moles of a reactant, it is necessary to observe the stoichiometric ratio between them:
Analyzing the reaction, it is possible to see that the stoichiometric ratio is 1:2, so we can perform the following expression:
So, if there are 2 mols of Ca(OH)2:
Ca(OH)2 | H2O
Finally, just find the number of grams of water using your molar mass:
So, 72 grams are produced of water in this reaction.
Learn more about mole calculation in: brainly.com/question/2845237
The answer is (2) 2 pairs. The oxygen atoms combine to get stable structure. So after the combination, each atom needs to have 8 electrons. So when they share 4 electrons can satisfy this requirement. Then there are 2 pairs shared.
