i. What is meant by periodicity in properties of elements with reference to the periodic table? ii. Why do all the elements of the same group have similar properties? iii. How will the tendency to gain electrons change as we move from left to right across a period? Why?

Question

Philoid · Accepted Answer

i. When elements are arranged in increasing order of their atomic number, elements repeat its property after certain elements, this repetition of the property is called periodicity of properties.

ii. Elements of the same group have the same properties because of:

1. A same number of valence electrons in the outermost shell.

2. Same valency

Examples: 1) In group 1 of alkali metals they all (Li, Na, K, Rb, Cs, Fr) have similar property due to the same number of valence electrons (equal to 1) and valency (equal to 1).

2) In group 17 of alkali metals, they all (F, Cl, Br, I ) have similar property due to the same number of valence electrons (equal to 7) and valency (equal to 1).

i. What is meant by periodicity in properties of elements with reference to the periodic table?ii. Why do all the elements of the same group have similar properties?iii. How will the tendency to gain electrons change as we move from left to right across a period? Why?

i. What is meant by periodicity in properties of elements with reference to the periodic table?
ii. Why do all the elements of the same group have similar properties?

iii. How will the tendency to gain electrons change as we move from left to right across a period? Why?