Trends In The Periodic Table

Question 1

The atomic radius ( covalent radius)

Answer 1

Half the distance between the nuclei of two atoms of the same element that are joined together by a single covalent bond

Question 2

Why does the atomic radius increase down the groups?

Answer 2

1. New energy level

2. Screening effect

Question 3

Why does the atomic radius decrease across the periodic table

Answer 3

1. Increase in effective nuclear charge

2. No increase in screening effect

Question 4

First ionisation energy

Answer 4

The minimum energy required to completely remove the most loosely bound electron from a neutral gaseous atom in its ground state

Question 5

Why does the first ionisation energy decrease down the group ?

Answer 5

1. Increasing atomic radius

2. Screening effect

Question 6

Why does the first ionisation energy increase across the period tabke

Answer 6

1. Increasing effectibe nuclear charge

2. Decreasing atomic radius

Question 7

Second ionisation energy

Answer 7

The energy required to remove an electron from an ion with one positive charge in the gaseous state. This means the energy required to carry out the following

X+ -> X2+ + e-

Question 8

Why do the values of the electronegativity decrease down the group

Answer 8

1. Increasing atomic radius

2. Screening effect of inner electrons

Question 9

Why does the electronegativity value increase across the periodic table?

Answer 9

1. Increasing effective nuclear charge

2. decreasing atomic radius