GED Science TestPhysical ScienceEasy
A scientist is investigating the properties of a noble gas. They observe that the gas is chemically inert and does not readily form compounds with other elements. Which of the following is the primary reason for this characteristic?
- AIts low boiling point
- BIts high atomic mass
- CIts full outermost electron shell
- DIts gaseous state at room temperature
Show answer & explanationAnswer & explanation
Correct answer: C. Its full outermost electron shell
Noble gases are characterized by their full outermost electron shells, which makes them very stable and unreactive. This electron configuration means they do not need to gain, lose, or share electrons to achieve stability, hence their chemical inertness.
Why the other options are wrong
- A. A low boiling point is a physical property related to intermolecular forces, not the chemical reactivity or inertness of the gas.
- B. High atomic mass does not directly explain chemical inertness; many reactive elements have high atomic masses.
- D. Being a gas at room temperature is a physical property, not a chemical one, and doesn't explain inertness.
Noble Gas Stability
Noble gases are a group of chemical elements with similar properties; under standard conditions, they are all odorless, colorless, monatomic gases with very low chemical reactivity.
- Located in Group 18 of the periodic table.
- Have a full valence electron shell (octet rule satisfied, except for helium with a duet).
- This electron configuration makes them highly stable and chemically inert.
Memory trick: Noble gases are naturally 'full' and don't need to 'share' their electron 'shelter'.