Oxygen & Silicone.
The two most common elements in the Universe, and in most stars are - in that order - hydrogen and helium (elements #1 and #2).
Oxygen and silicon are the two most abundant elements found in the most common minerals. The most common minerals found on Earth are silicates.
Hydrogen and Helium are the two most common elements in the universe.
Hydrogen and helium.
This question depends on what importance is being assigned. The most common dissolved ions (elemental atoms do not dissolve) are sodium and chloride, but they are many other important elements found in sea water.
Hydrogen, followed by helium.
Hydrogen and helium.
oxygen and silicon
Dirt and Dirt!
the most common element is hydrogen and its molecule of two hydrogen atoms is the most common molecule
silicon and oxygen
Quartz and feldspars are the most common silicate minerals of the crust.