Question

Give three examples of gaseous elements that exist as diatomic molecules. Give three examples of gaseous elements that exist as monatomic species.

Short answer

Three examples of gaseous elements that exist as diatomic molecules are Hydrogen (H2), Nitrogen (N2), and Oxygen (O2). Three examples of gaseous elements that exist as monatomic species are Helium (He), Neon (Ne), and Argon (Ar).

Step-by-step solution

Diatomic Molecule Example 1

Hydrogen (H2) is a diatomic molecule, as it consists of two hydrogen atoms bonded together.

Diatomic Molecule Example 2

Nitrogen (N2) is another example of a diatomic molecule. It is composed of two nitrogen atoms bonded together.

Diatomic Molecule Example 3

Oxygen (O2) is the third example of a diatomic molecule. It is made up of two oxygen atoms bonded together.

Monatomic Species Example 1

Helium (He) is a monatomic species, as it exists as a single helium atom.

Monatomic Species Example 2

Neon (Ne) is another monatomic species. It exists as a single neon atom.

Monatomic Species Example 3

Argon (Ar) is our third example of a monatomic species. It exists as a single argon atom.

Key concepts

Diatomic Molecules

Diatomic molecules are molecules that consist of exactly two atoms bonded together. In particular, diatomic molecules often refer to the simplest forms of molecules where the two atoms are of the same element. In chemistry, these molecules are essential because they help explain the behavior and characteristics of various elements, especially those in the gaseous state.

Common diatomic molecules in the gaseous phase include:

• Hydrogen ( H_2 ): The simplest and most abundant element in the universe, hydrogen naturally forms diatomic molecules. Each molecule is made up of two hydrogen atoms bonded together.
• Nitrogen ( N_2 ): Comprising roughly 78% of the Earth's atmosphere, nitrogen mostly exists as a diatomic molecule. Two nitrogen atoms bond to form this stable molecule.
• Oxygen ( O_2 ): Critical for life on Earth, oxygen is most commonly found as a diatomic molecule. Two oxygen molecules form the breathable oxygen in our atmosphere.

Note, other elements like fluorine and chlorine also form diatomic molecules when in gaseous form. These diatomic molecules are covalently bonded, sharing electrons between the atoms to achieve stability.

Monatomic Species

Monatomic species are elements that exist as single, unbonded atoms, rather than as molecules. This characteristic is prevalent among the noble gases like helium, neon, and argon. Each of these elements naturally prefers to remain as individual atoms due to having full outer electron shells. This full electron shell provides exceptional stability and low reactivity.

Examples of monatomic gaseous elements include:

• Helium (He): Helium is an inert gas, meaning it does not readily react with other elements. It is used in various applications, including airships and weather balloons, because of its low density compared to air.
• Neon (Ne): Known for its bright glow when electrified, neon is a monatomic species utilized in advertising signs and lighting.
• Argon (Ar): This odorless and colorless gas is often used to provide an inert atmosphere in industrial applications. Like helium and neon, argon exists as single atoms.

The inertness and stability of monatomic species make them essential in areas where reactivity with other elements must be minimized.

Gaseous Elements

Gaseous elements are those that take the form of either diatomic molecules or monatomic species under standard conditions of temperature and pressure (0°C, 1 atm). Understanding the state of these elements is crucial in grasping their chemical properties and how they interact with other substances.

• Diatomic Gaseous Elements: Elements like hydrogen, nitrogen, and oxygen naturally occur as diatomic molecules in their gaseous forms. These elements are vital in numerous biological and chemical processes.
• Monatomic Gaseous Elements: The noble gases such as helium, neon, and argon exist as monatomic species. These elements are almost completely inert, making them useful in fields that require non-reactive environments.

It is essential to differentiate between diatomic and monatomic gaseous elements to predict their behavior in different reactions. Generally, gaseous elements exhibit unique bonding and electron configurations that play a significant role in their reactivity and usage in various applications.