What was johann dobereiner’s contribution to the development of the periodic table? he arranged the elements according to increasing atomic mass. he arranged the elements according to increasing atomic number. he identified triads of elements that had similar properties. he organized elements into four groups based on their properties.

He discovered what became known as Dobereiner's triads.  For example he noticed that the average of the atomic mass of lithium and potassium was close to the atomic mass of sodium and they had similar properties.

The third choice is the correct one.

He identified triads of elements that had similar properties.

Explanation:

He identified a group of there elements that have relatable physical properties such their atomic weight and density. For example in alkali metals such as lithium, sodium and potassium, the atomic weight of sodium is the arithmetic mean of the first and the third element. The same trend was observed with alkaline earth metals (calcium, strontium and barium), halogen (chlorine, bromine and iodine) and chalcogens (sulphur, selenium and tellurium).

no, i was listening to water by schoolboy q while and i saw this question

explenation:

water isn't wet. wetness is a description of our experience of water; what happens to us when we come into contact with water in such a way that it impinges on our state of being. we, or our possessions, 'get wet'. a less impinging sense experience of water is that it is cold or warm, while visual experience tells us that it is green or blue or muddy or fast-flowing. we learn by experience that a sensation of wetness is associated with water: 'there must be a leak/i must have sat in something.'