Helium is used as it is/pure. Helium is an inert gas and does not form part of compounds.
Well, probably...
If helium used is pure and if there is no electric discharge, then chemically helium in both the cases will be same.
Gold is used usually in pure form or as an alloy.
Pure water is a compound. it is not a mixture.
The gas that is used for welding is a pure hydrocarbon compound (C2H2).
No. Helium is one of the lightest elements in the world and is not commonly used in any form of transportation. To answer your question the compound used to lift rockets is liquid oxygen.
As breathing gas for diving: A mixture of oxygen and helium (some times containing nitrogen or a small percentage of oxygen) is used to avoid the phenomenon of narcosis when only pure oxygen is used; also helium make the effort for breathing easier.
The physical properties of a pure substance can be used to identify it. A pure substance is an element or a compound, not a mixture.
The answer would be no. In Earth there is no hydrogen source in its pure form. It is only found in compound with other elements.
Its a compound and a pure chemical substance
Salt is a compound made from Sodium and Chlorine. Its chemical formula is NaCl.Although made from two separate elements, a handful of salt is a pure substance not a mixture because it is a compound.
Neon is an element . . . one of the noble gases.