Question

a solid substance composed of positive and negative ions

Answer 1

Metals often react with nonmetals to form ionic compounds. These compounds are composed of positive and negative ions formed by adding or subtracting electrons from neutral atoms and molecules.

Answer 2

Answer:

Salt crystals are made by ions. Salt crystal is made up of positive and negative charged ions formed by adding or removing electrons from atoms and molecule. Metals react with nonmetal that can form a ionic compound. When sodium molecule reacts with chlorine molecule it makes a sodium chloride which is a salt.

In this reaction all sodium atom donates an electron to chlorine atom and become positively charge whereas chlorine gains electrons and it becomes negatively charge. Now negative chlorine ion attract positive sodium ion and forms a ionic compound or salt crystal.

                                  $2 \mathrm{Na}^{+}+\mathrm{Cl}_{2} \rightarrow 2 \mathrm{NaCl}$