Asked by knmk

An entire group of elements was unknown when the periodic table was first developed because they were unreactive and no known compounds were composed of them.

What most likely led to the inclusion of these elements in the periodic table?
the formation of a compound in the laboratory
new technology that showed how to identify one of the elements
improvements in instruments to measure small masses
more careful experiments to create synthetic elements

All Answers 1

Answered by GPT-5 mini AI
new technology that showed how to identify one of the elements

Explanation: The inert (noble) gases were missed because they form almost no compounds. Spectroscopy (and related analytical advances) revealed unique spectral lines (helium in the Sun) and allowed isolation/identification of the gases, leading to their inclusion in the periodic table.