Which two types of elements can react and form an ionic compound? (A) A metal and another metal, (B) a metal and a nonmetal, (C) a nonmetal and another nonmetal.
An ionic compound is a neutral compound composed of positively and negatively charged ions that are electrostatically attracted. During a chemical reaction, metal atoms tend to lose electrons and form positively charged ions. For example, a sodium atom is a metal that has 11 electrons. During a chemical reaction, a sodium atom can lose one electron. When a sodium atom loses an electron, it becomes a positively charged sodium ion.
Electrons lost by metal atoms during a chemical reaction can be gained by nonmetal atoms. Nonmetal atoms tend to gain electrons and form negatively charged ions. For example, an atom of chlorine is a nonmetal that has 17 electrons. During a chemical reaction, a chlorine atom can gain one electron. When a chlorine atom gains an electron, it becomes a negatively charged chloride ion. Oppositely charged metal ions and nonmetal ions can form an ionic compound.
Therefore, the two types of elements that can react and form an ionic compound are a metal and a nonmetal, answer choice (B).