The periodic table

Question 1

What are the vertical columns called?

Answer 1

Groups

Question 2

What are the horizontal rows called?

Answer 2

Periods

Question 3

Why do trends exist?

Answer 3

Because of similar atomic structure

Question 4

What are periodic trends?

Answer 4

Elements in the same group will have similar chemical properties due to the same number of valence electrons

Question 5

What are valence electrons?

Answer 5

Elements in the same group have the same number of electrons in outer energy level

Question 6

What are the properties of valence electrons?

Answer 6

Determines chemical properties
Involved in chemical bonding

Question 7

What is the reactivity of noble gases?

Answer 7

Chemically inert
Outer energy level full
Stable

Question 8

What is the reactivity of other atoms?

Answer 8

Chemically reactive
Outer energy level not full
Unstable
Tends to gain or lose electrons in such a way that outer energy level becomes full

Question 9

What is valency?

Answer 9

The number of electrons an atom must gain or lose or share to achieve the stability of a noble gas.

Question 10

How do you achieve a negative charge or positive charge?

Answer 10

Atoms gain electrons - more electrons than protons - negative charge anion

Atoms lose electrons - less electrons than protons - positive charge cation

Question 11

What is atomic radius?

Answer 11

A measure of the size of atoms. The distance between the last orbital and nucleus

Question 12

Explain trends of atomic radius.

Answer 12

Atomic radius increases from top to bottom down a group:
- the number of energy levels increases
- electrons further away from nucleus

Atomic radius decrease from left to right in a period:
- same number of energy levels
- more protons in nucleus - stronger electrostatic force between nucleus & the electrons - electrons pulled closer to nucleus -atomic radius smaller

Question 13

What is ionisation energy?

Answer 13

The amount of energy needed to remove the most loosely held electron from a neutral atom in the gas phase.

Question 14

What does it mean when there is a high ionisation?

Answer 14

More difficult to remove electrons

Question 15

Explain ionisation levels.

Answer 15

1st ionisation energy - remove 1st electons from neutral atom

2nd ionisation energy - remove 2nd electron from a ion

3rd ionisation energy - remove 3rd electron from ion

Question 16

Explain trends of ionisation energy.

Answer 16

Ionisation energy decreases from top to bottom down a group:
- the no. of energy levels increases
- es you go down a group, the electrons are further away from the nucleus
- Electrostatic force between electrons and nucleus gets weaker
- less energy is needed to remove the electrons

Ionisation energy increases from left to right in a period:
- same number of energy levels
- more protons in nucleus
- stronger electrostatic force between the nucleus and the electrons
- more energy needed to remove the electrons

Question 17

What is the difference of ionisation between metals and non-metals?

Answer 17

Metals tend to lose electrons rather than gain - low ionisation energy

Non-metals tend to gain electrons rather than lose - high ionisation energy

Question 18

What is the definition of electron affinity?

Answer 18

the energy released when an electron is added to a neutral atom in the gas phase to form a negative ion.