Identify the elements that have molecules as their basic units. a. hydrogen b. iodine c. lead d. oxygen

Verified step by step guidance

1. Identify the elements from the list that are nonmetals, as nonmetals typically exist as molecules in their elemental form.
2. Recall that hydrogen (H2) and oxygen (O2) are diatomic molecules, meaning they naturally form molecules consisting of two atoms.
3. Recognize that iodine (I2) typically exists as a diatomic molecule as well.
4. Understand that lead (Pb) is a metal and does not form molecules as its basic units; instead, it exists in atomic or ionic forms.
5. Conclude that the elements hydrogen, iodine, and oxygen have molecules as their basic units, while lead does not.

Key Concepts

Molecular Elements

Molecular elements are substances that consist of molecules as their basic units. These molecules are formed when two or more atoms of the same element bond together. Common examples include diatomic molecules like hydrogen (H2) and oxygen (O2), where the atoms are identical and share electrons to achieve stability.

Atomic vs. Molecular Substances

In chemistry, substances can be classified as atomic or molecular. Atomic substances consist of single atoms, such as noble gases like helium, while molecular substances are composed of two or more atoms bonded together. Understanding this distinction is crucial for identifying which elements form molecules as their basic units.

Diatomic Elements

Diatomic elements are a specific category of molecular elements that exist naturally as pairs of atoms. The seven diatomic elements include hydrogen (H2), nitrogen (N2), oxygen (O2), fluorine (F2), chlorine (Cl2), bromine (Br2), and iodine (I2). Recognizing these elements helps in determining which ones have molecules as their fundamental units.