I think the correct answers from the choices listed above are the first, third and the last option. Ionic compounds are compounds that dissociates into ions when in aqueous solution. From the list, NH4Cl, KF and MgO are the ionic compounds. Hope this answers the question.
Answer:
c- dry cells can not be recharged
The correct number of significant figures and digits is 3
Isotopes are atoms of the same element that<span> has different masses.</span>
