Disadvantages of modern periodic table?
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Position of hydrogen is not satisfactory, it can be placed either in group I or 17 group of the first period.

It fails to accommodate lathanides and actinides in the main body of the periodic table. These are kept separately at the bottom of the periodic table.

It has its elements with mass numbers phrased in many decimal places, it requires one to round off to get the actual value.

The atomic numbers of some elements such as Protonium were just guessed.

specific gravity is the density of a substance divided by the density of water. since (at standard temperature and pressure) water has a density of 1 gram/cm3, and since all of the units cancel, specific gravity is usually very close to the same value as density

so "c" is the answer

plz give brainliest