The pair of elements that will form an ionic bond are Strontium and Chlorine.
Mass and atoms are the properties conserved in every ordinary chemical reaction.
Hope this helps!
Explanation:
The given data is as follows.
Mass of a lead atom = 
Volume = 2.00 
Density = 11.3 
As it is mentioned that 1 cubic centimeter contains 11.3 grams of lead.
So, in 2 cubic centimeter there will be 
of lead atoms.
One lead atom has a mass of . Therefore, number of atoms present in 22.6 g of lead will be as follows.
= 
Thus, we can conclude that there are of lead are present.
Nitrogen makes up around 78% of the total atmosphere.
Answer is: Allena is correct. It is an element because it is only made of chlorine atoms.
A chemical element bonded to an identical chemical element is not a chemical compound since it is made from only one element and not from two different elements. Chlorine is molecule, but not compound.
