Which element is a gas at stp? 1)sulfur 2)xenon 3)potassium 4)phosphorus

Hello!

The element that is a gas at STP is Xenon

STP refers to Standard Temperature and Pressure, and corresponds to a Temperature of 0°C (273,15 K) and a Pressure of 1 atm.

From the list, Sulfur, Potassium and Phosphorus are solid at STP, while Xenon is located in the Group 18 of the periodic table, also called the "Noble Gases".

The elements in Group 18 have their valence shell completely filled with electrons, so they don't have strong interactions with themselves and neither with other elements. That means that they are found in the gaseous state, due to their weak intermolecular interactions.

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