Because it has it has eight electrons in the outermost occupied energy level.
Krypton and the other elements in group 18 comprise the noble gases. See links below.
Group 18 is the noble gases, the last group on the periodic table. The elements are Helium, Neon, Argon, Krypton, Xenon, and Radon. These elements have a full outer shell and are virtually nonreactive.
As with all six noble gases, Krypton is colourless and odourless. It belongs to group 0 or group 18 of the periodic table of elements.
Neon belongs to group of noble gases. The other elements are Helium, Argon, Krypton, Xenon and Redon.
The Noble gasses. Neon, Argon, Xenon, Radon, Krypton and Helium
Krypton belongs to the Inert or Noble gases group or chemical family in the Periodic Table.
Krypton and the other elements in group 18 comprise the noble gases. See links below.
Group 18 is the noble gases, the last group on the periodic table. The elements are Helium, Neon, Argon, Krypton, Xenon, and Radon. These elements have a full outer shell and are virtually nonreactive.
There are six noble gases: helium, neon, argon, krypton, xenon and radon
The elements from the noble gases group include: helium,neon,argon,krypton,xenon,radon and ununoctium.
Noble gases are: helium, neon, argon, krypton, xenon, radon, ununoctium.
All of the group 8 (group 0) elements - Helium, Neon, Argon, Krypton, Xenon, Radon
group 18. Noble gases family contain: helium, neon, argon, krypton, xenon, radon and ununoctium.
All group 18 elements (helium, neon, argon, krypton, xenon, radon) are noble gases.
Group 18 elements are the noble gases. There are six noble gases: helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe) and radon (Rn)
hydrogen is in group 1, the rest in noble gases (group 18)
Krypton belongs to the Noble Gas Family or the Inert Gas Family.