6.7 mass because 1 atom equals 6.3 but if u add 4 it would be 6.7
https://www.khanacademy.org/science/chemistry/chemical-reactions-stoichiome/balancing-chemical-equations/v/balancing-chemical-equations-introduction
this will help trust me
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Answer:
Anion is negatively charged particle.
Calcium +2. Its cation
Oxygen -2
Explanation:
An anion is a charged particle with a negative charge. Anions has charge of -1
Oxygen require two electrons to complete its octet and hence its charge is -2
Calcium is a cation and has a positive charge of +2
