Krypton

NOBLE GAS

Bohr Model: Electrons arranged in energy shells around the nucleus.

Krypton (from Greek:κρυπτός kryptos "the hidden one") is a chemical element with symbol Kr and atomic number 36. It is a member of group 18 (noble gases) elements. A colorless, odorless, tasteless noble gas, krypton occurs in trace amounts in the atmosphere, is isolated by fractionally distilling liquefied air, and is often used with other rare gases in fluorescent lamps.

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Quick Facts

Atomic Number 36

Period 4

Group 18

Phase Gas

Appearance colorless gas, exhibiting a whitish glow in a high electric field

About Noble Gass

Noble gases are colorless, odorless, and extremely unreactive (inert) due to having full valence electron shells.

History

Discovered By William Ramsay

Named By Unknown

Physical Properties

Atomic Mass 83.7982

Density 3.749 g/L

Molar Heat N/A J/(mol·K)

Phase Transition (Melting & Boiling Points)

Krypton melts at 115.78 K and boils at 119.93 K.

Atomic Properties

Electron Config [Ar] 3d10 4s2 4p6

Electronegativity 3

Electron Affinity -96 kJ/mol

Ionization Energy 1350.8 kJ/mol

Orbital Filling Diagram

This diagram visualizes electron configuration according to the Aufbau principle and Hund's rule. Boxes represent orbitals (s, p, d, f), while arrows indicate electrons with spin up or down. Electrons fill lower energy levels first and occupy orbitals singly before pairing.

Emission Spectrum Emission spectrum of Krypton

Photograph

Source: Wikipedia

External Resources

Wikipedia PubChem Royal Society of Chemistry Periodic Videos (YouTube)

Study Guide

Atomic Number

The number of protons in the nucleus, which defines the element.

Atomic Mass

The average mass of an atom, including protons and neutrons.

Electronegativity

A measure of how strongly an atom attracts electrons in a bond.

Ionization Energy

The energy required to remove an electron from an atom.

Electron Config

The arrangement of electrons in the atom's energy shells.