Answer:-
molecules.
Solution:- The grams of tetrabromomethane are given and it asks to calculate the number of molecules.
It is a two step unit conversion problem. In the first step, grams are converted to moles on dividing the grams by molar mass.
In second step, the moles are converted to molecules on multiplying by Avogadro number.
Molar mass of
= 12+4(79.9) = 331.6 g per mol
let's make the set up using dimensional analysis:

=
molecules
So, there will be
molecules in 250 grams of
.
Answer:

Explanation:
Hello!
In this case, since calcium's oxidation state when forming ionic bonds is +2 and sulfur's oxidation state when bonding those bonds is -2, for the required formula we write:

Now, since they have the same charge number, we infer the ionic compound formed when they bond is calcium sulfide:

Best regards!
Answer:
a..312 I guesss kkkkkkkkkkkkkkkkkk