Hydrogen and oxygen are already elements. Elements do not contain other elements.
they are chemical elements
What you have listed are not elements (except for the 'native elements'), they are classifications of minerals.
Group 1 Elements (elements in the first group [column]) are classed as Alkali Metals. Group 2 Elements (elements in the second group [column]) are classed as Alkaline Earth Metals. All elements not in a representative group are classed as Transition Metals. Group 3 Elements (elements in the third full group [coulumn]) are classed as Earth Metals
Elements that cannot be controlled.
Elements can belong to subsets. Subsets can be elements of sets that are called "power sets".
A R. Powell has written: 'The analysis of minerals and ores of the rarer elements'
H. R. Byers has written: 'Elements of cloud physics'
R. J. Puddephatt has written: 'The periodic table of the elements'
potassium, carbon and oxygen
R. Mulvihill has written: 'The relative importance of elements of low-rise housing estates'
R. W. Cushman has written: 'Elements of success' -- subject(s): Success
Here are the first 10 elements on the Periodic Table from 1 to 10.HydrogenHeliumLithiumBerylliumBoronCarbonNitrogenOxygenFluorineNeon
N. R. Dhanraj has written: 'Elements of maintaining quality in the operation of a flexible manufacturing system'
Don R. Marshall has written: 'The Four Elements of Successful Management' -- subject(s): Management
Ian R. Brown has written: 'The elements of pre-project control of a North Sea project'
alloys r homagenous mixture of two or more elements