Trends In The Periodic Table (chpt. 7)

Question 1

Heisenberg’s Uncertainty Principle

Answer 1

It is impossible to measure at the same time both the velocity and position of an electron

Question 2

Atomic radius

Answer 2

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

Question 3

First ionisation energy

Answer 3

The energy required to remove the most loosely bound electron from a neutral gaseous atom

Question 4

Electronegativity

Answer 4

The relative attraction that an atom in a molecule has for the shared pair of electrons in a covalent bond

Question 5

Second ionisation energy

Answer 5

The energy required to remove an electron from an ion with one positive charge in the gaseous state

Question 6

Trends in first ionisation energy across period & down group

Answer 6

Across period - increases
Increasing effective nuclear charge
Decreasing atomic radius

Down group - decreases
Increasing atomic radius
Screening effect

Question 7

Trends in atomic radius across a period and down a group

Answer 7

Decrease across a period
Increase in effective nuclear charge
No increase in screening effect

Increase down a group
Screening effect
New energy levels