Question

argon is kept before potassium in modern periodic table why
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Answer 1

Explanation:

This is because modern periodic table is according to icnreasing atomic numbers. Since Ar has the atomic number 18 and potassium 19 so Argron is placed before K in the Modern periodic table.

Answer 2

Answer:

The modern periodic table is sorted by ascending atomic number, not mass number. Argon is heavier but has 18 protons, Potassium has 19. Same deal with Tellurium and Iodine. The table was originally laid in increasing mass but it was discovered that the properties of the elements varied periodically when they were sorted according to the number of protons.