The cations has positive charges that are metals while the anions have negative charges that are non-metals. Upon reaction, there is an exchange in charges that are reflected in the subscripts of the atoms. In this case, compound AX2 must have a cation, A belonging to group 2 A with +2 charge and anion, X belonging to Group 7A with -1 charge. Answer is D.
<u>Answer:</u> The number of carbon and oxygen atoms in the given amount of carbon dioxide is
and
respectively
<u>Explanation:</u>
To calculate the number of moles, we use the equation:

Given mass of carbon dioxide gas = 3.45 g
Molar mass of carbon dioxide gas = 44 g/mol
Putting values in above equation, we get:

1 mole of carbon dioxide gas contains 1 mole of carbon and 2 moles of oxygen atoms.
According to mole concept:
1 mole of a compound contains
number of molecules
So, 0.0784 moles of carbon dioxide gas will contain
number of carbon atoms and
number of oxygen atoms
Hence, the number of carbon and oxygen atoms in the given amount of carbon dioxide is
and
respectively
<h3>I hope it is helpful for you ....</h3>
The amount of matter in an object is consisted to be MASS .