The answer depends on the type of experiment.
While these elements have several things in
common, they have many differences as well,
including (just to name a few), their atomic size
(the atoms get bigger going down the chart), their
density (helium is lighter than air, but argon is
heavier than air), and their boiling points.
For some experiments, these differences may not
matter, for example if you simply need a
non-reactive gas. For other experiments, their
differences may matter, and a scientist may even
want to take advantage of those differences. For
example, compressed liquid helium is commonly used
in science because it is VERY cold, just 4 Kelvin.
Neon, argon and the rest of the group 8 elements
cannot get this cold when liquefied. Neon can be
used for red light emission (like in neon signs),
but helium cannot.
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