Answer:
NaCl (Na is a metal and Cl is a nonmetal) MgO (Mg is a metal and O is a nonmetal) Al2O3, NaF, Na2O
Explanation:
You have to have a metal and a non metal together for it to be ionic
When your substance either; change color, start to smell, explode, form bubbles, precipitate, and/or get hotter or colder.
The graph would not have plummeted if various species were planted due to improvement of the potato crops.
<h3>What is variety?</h3>
The term variety has to do with the planting of different species of plants on the same farm. We know that the planting of different species of the same crop helps to improve the resistance to diseases of a plant.
Hence, the graph would not have plummeted if various species were planted due to improvement of the potato crops.
Learn more about improved specie:brainly.com/question/3627477
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Potassium chloride
Potassium is the metal cation and chloride is the nonmetal anion
All the other options have two non metals