I am pretty sure this has to do with the fact that there are differences between the elements.
Minerals vary in ways they can be distinduished. Some are easy to identify by hardness, color , streak, or luster
Some minerals are easier to identify than others because many have unique properties that make them different. For example gold is a very heavy metal and is extremely "soft" unlike "fools gold" which is brittle and cant be shaped. They are both similar in appearance but extremely different in traits.
The elements are identified by atomic number. The atomic number is equal to the number of protons in each atom of the element. Of course the elements are usually identified their symbols, which are arbitrary.
Hydrogen and oxygen are already elements. Elements do not contain other elements.
combinations
H
Minerals vary in ways they can be distinduished. Some are easy to identify by hardness, color , streak, or luster
Some minerals are easier to identify than others because many have unique properties that make them different. For example gold is a very heavy metal and is extremely "soft" unlike "fools gold" which is brittle and cant be shaped. They are both similar in appearance but extremely different in traits.
Some mixtures are easier to seperate than others because some mixtures are heterozygous mixtures. These mixtures are easier to seperate then others because you can see what is in them so you would know how to get them out.
Some people find rational fractions easier, others prefer decimals fractions. For some purposes rational fractions are simpler, for others decimals are easier. So there is no simple answer.
Elements are looking to find the magic number which is 8. when an atom has 8 electrons it is the most stable. Bonds that will have a total of 8 electrons work easier than bonds that will have 3 or 4.
The character(s) used to identify an element depends on the element. For example, one character elements can be S (sulfur), O (oxygen), N (Nitrogen) etc. Some example of two letter elements might be sodium (Na), silver (Ag), gold (Au), magnesium (Mg), and others.
Not in the "natural" elements (the first 92), but we know of no limit to the trans-urantic elements. A2: Some gases were first discovered by their spectrums--the yellow line of helium in the sun was observed long before it was found on earth.
Some people find calculus easier, others find physics easier. There is no general answer.
Hydrogen, Oxygen, Potassium, some others
Yes for some, no for others.
d