Water is a/an ----made up of hydrogen and oxygen combined in the ratio ---by volume or ---by mass.

Hint: We know that water is an inorganic, straightforward, bland, unscented, and almost boring compound substance, which are the principal constituent of Earth's hydrosphere and the liquids of all known living organic entities. It is essential for all known types of life, despite the fact that it gives no calories or natural supplements. Its compound recipe is \[{H_2}O\], implying that every one of its particles contains one oxygen and two hydrogen molecules, associated by covalent bonds. Two hydrogen molecules are connected to one oxygen iota at a point of \[104.45^\circ \].

Complete answer:
We must have to know that the water particles include the mixes of hydrogen and oxygen iotas in a \[2:1\] proportion. Since they are available in a fixed proportion of mass, water atoms submit to the law of consistent extents. Water is shaped when two atoms of the diatomic hydrogen gas join with one particle of the diatomic oxygen gas to create two atoms of water.
We have to remember that water is a substance composed of hydrogen and oxygen consolidated in the proportion \[2:1\] by volume or \[1:8\] by mass (Two gram of hydrogen joins with \[16g\] of oxygen).

Note:
We must have to remember that mists consist of suspended drops of water and ice, its strong state. At the point when finely isolated, glasslike ice may be encouraged as snow. Water covers \[71\% \] of the Earth's surface, for the most part in oceans and oceans. Small segments of water happen as groundwater\[\left( {1.7\% } \right)\], in the ice sheets and the ice covers of Antarctica and Greenland\[\left( {1.7\% } \right)\], and noticeable all around as fume, mists and precipitation\[\left( {0.001\% } \right)\]. Water moves constantly through the water pattern of dissipation, happening (evapotranspiration), buildup, precipitation, and spillover, as a rule arriving at the ocean.