Question

state of periodic law and explain how it was arrived at in what various ways does it help this chemist​

Answer 1

The Periodic Law states that the physical and chemical properties of the elements recur in a systematic and predictable way when the elements are arranged in order of increasing atomic number.

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Answer 2

Answer:

The Periodic Law is based on the observation that starting from Hydrogen, atomic number 1, running all the way up to Uranium, atomic number 92; the chemical and physical properties of the elements are fairly similar at regular intervals. That is why the elements in the periodic table are arranged the way they are reflecting this periodicity. For example Lithium, Sodium, Potassium, Rubidium, & Caesium all have a valency of 1. Similarly Beryllium, Magnesium, Calcium, Strontium, Barium, and Radium all have a valency of 2.

Periodicity is the conclusion that has been reached comparing and contrasting the physical and chemical properties of all the elements. A pattern in their behaviour can be seen.

If this is a homework question this is not a simple question. You need to be familiar with all the chemistry you studied up to the age of 16 to notice there is a pattern in the properties of the elements.

Other periodic or recurring trends in the properties of the elements include;

Increase/ decrease on Atomic radius, Ionisation energy, Electron affinity, Non-metallic character, Metallic character. You need to review what Ionisation energy, and Electron Affinity means if you are not familiar with those concepts.

'A' level chemistry textbooks will have a chapter about Periodicity.