Recall that most atoms are stable when their outermost ring has eight electrons. (Some atoms, such as lithium and beryllium, are stable when their outermost ring has two electrons.)
Answer:
5SiO2 + 2CaC2 --> 5Si + 2CaO + 4CO2
4NH3 + 5O2 --> 4NO + 6H2O
I am pretty sure that the statement which is true is A. a molecule having a covalent bond can be ionic. I choose this option because you usually ca see how electons of polyatomic ions are being covalenr and gain or loose ionic electrons in order to accomplish the octet.<span>
</span>Do hope you find it helpful! Regards.