1.2.1
The Periodic Table
Test your knowledge with free interactive questions on Seneca — used by over 10 million students.
The Periodic Table - Groups and Periods
The periodic table is arranged into periods and groups.

The periodic table
- The periodic table is the table that organises all the elements into groups and periods.
- The elements are arranged in order of proton number, starting with hydrogen that has the proton number of 1.

Periods
- A period is a row in the periodic table.
- Elements in the same period have their valence electrons in the same shell.
- The diagram highlights Period 3.

Period example
- Magnesium and sulfur are in the same period.
- In simple terms, they have the electron configuration 2,8,2 and 2,8,6 respectively.
- So, their valence electrons are in the same shell.
,h_400,q_80,w_640.png)
Groups
- A group is a column in the periodic table.
- Elements in the same group have their electrons in similar orbitals.
- They often have very similar properties.
- A Group n element has n valence electrons.
- E.g. Carbon is in Group 4 and has 4 valence electrons.
- The diagram highlights Group 7.
,h_400,q_80,w_640.png)
Group example
- The halogens are all in Group 7.
- Fluorine's simplified electron configuration is 2,7.
- Chlorine's is 2,8,7.
- We see they both have the same number of valence electrons.
- We also know that halogens have very similar chemical properties.
Periodic Table - Blocks
The periodic table can be organised into four sections. These are labelled s, p, d and f blocks.
,h_400,q_80,w_640.png)
The s block
- The two leftmost columns make up the s block.
- This is called the s block because elements in it have all their valence electrons in s orbitals.
- Note, Helium is also an s block element because it has the electron configuration 1s2.

The p block
- The six rightmost columns make up the p block.
- This is called the p block because elements in the p block have a partially filled p sub-shell.

The d block
- The d block lies between the s and p blocks.
- Elements in the d block have a partially filled d sub-shell.
- Elements in the d block are often called transition metals.
,h_400,q_80,w_640.png)
The f block
- The f block is detached along the bottom of the periodic table.
- Elements in the f block have a partially filled f sub-shell.
- These elements are referred to as the lanthanides and the actinides (top and bottom row respectively).
1Principles of Science I
1.1Structure & Bonding
1.1.1Atomic Model1.1.2Electron Shells, Sub-Shells & Orbitals1.1.3Ionic Bonding1.1.4Representing Ionic Bonds1.1.5Covalent Bonding1.1.6Representing Covalent Bonds1.1.7Metallic Bonding1.1.8Intermolecular Forces1.1.9Intermolecular Forces 21.1.10End of Topic Test - Bonding1.1.11Relative Masses1.1.12The Mole1.1.13Molar Calculations1.1.14Molar Calculations 21.1.15Empirical & Molecular Formulae1.1.16Balanced Equations1.1.17Percentage Yield1.1.18End of Topic Test - Amount of Substance
1.2Properties of Substances
1.2.1The Periodic Table1.2.2Ionisation Energy1.2.3Factors Affecting Ionisation Energies1.2.4Trends of Ionisation1.2.5Trends in the Periodic Table1.2.6Polarity1.2.7Metals & Non-Metals1.2.8Alkali Metals1.2.9Alkaline Earth Metals1.2.10Reactivity of Alkaline Earth Metals1.2.11Redox1.2.12Transition Metals1.2.13Redox Reactions of Transition Metals
1.3Cell Structure & Function
1.4Cell Specialisation
1.5Tissue Structure & Function
1.5.1Human Gas Exchange1.5.2Blood Vessels1.5.3Atherosclerosis1.5.4Skeletal Muscle1.5.5Slow & Fast Twitch Fibres1.5.6Neurones1.5.7Speed of Transmission1.5.8Action Potentials1.5.9End of Topic Test - Neurones & Action Potentials1.5.10Synapses1.5.11Types of Synapse1.5.12Medical Application1.5.13End of Topic Test - Synapses1.5.14Chemical Brain Imbalances1.5.15Effect of Drugs on the Brain
1.6Working with Waves
1.7Waves in Communication
2Practical Scientific Procedures and Techniques
3Science Investigation Skills
3.1Scientific Processes
3.2Data Handling & Analysis
3.3Enzymes in Action
3.4Diffusion
3.5Plants & Their Environment
3.6Energy Content in Fuels
4Principles of Science II
4.1Extracting Elements
4.2Relating Properties to use of Substances
4.3Organic Chemistry
4.4Energy Changes in Industry
4.5The Circulatory System
4.5.1The Circulatory System4.5.2Blood Vessels4.5.3Blood Transfusion & the ABO Rhesus System4.5.4The Heart4.5.5The Cardiac Cycle4.5.6Cardiac Output4.5.7Coordination of Heart Action4.5.8Heart Dissection4.5.9Controlling Heart Rate4.5.10Electrocardiograms4.5.11Cardiovascular Disease4.5.12Investigating Heart Rates
4.6Ventilation & Gas Exchange
4.7Urinary System
4.9Thermal Physics
4.9.1Power & Efficiency4.9.2Work & Energy4.9.3Conservation of Energy4.9.4Pressure4.9.5First Law of Thermodynamics4.9.6Second Law of Thermodynamics4.9.7Heat Engines, Heat Pumps & Refrigerators4.9.8Non-Flow Processes4.9.9p-V Diagrams4.9.10Ideal Gases4.9.11Ideal Gases 24.9.12Thermal Energy Transfer4.9.13Thermal Energy Transfer Experiments
4.10Materials
5Contemporary Issues in Science
5.1Contemporary Issues in Science
5.2Analysing Scientific Information
Jump to other topics
1Principles of Science I
1.1Structure & Bonding
1.1.1Atomic Model1.1.2Electron Shells, Sub-Shells & Orbitals1.1.3Ionic Bonding1.1.4Representing Ionic Bonds1.1.5Covalent Bonding1.1.6Representing Covalent Bonds1.1.7Metallic Bonding1.1.8Intermolecular Forces1.1.9Intermolecular Forces 21.1.10End of Topic Test - Bonding1.1.11Relative Masses1.1.12The Mole1.1.13Molar Calculations1.1.14Molar Calculations 21.1.15Empirical & Molecular Formulae1.1.16Balanced Equations1.1.17Percentage Yield1.1.18End of Topic Test - Amount of Substance
1.2Properties of Substances
1.2.1The Periodic Table1.2.2Ionisation Energy1.2.3Factors Affecting Ionisation Energies1.2.4Trends of Ionisation1.2.5Trends in the Periodic Table1.2.6Polarity1.2.7Metals & Non-Metals1.2.8Alkali Metals1.2.9Alkaline Earth Metals1.2.10Reactivity of Alkaline Earth Metals1.2.11Redox1.2.12Transition Metals1.2.13Redox Reactions of Transition Metals
1.3Cell Structure & Function
1.4Cell Specialisation
1.5Tissue Structure & Function
1.5.1Human Gas Exchange1.5.2Blood Vessels1.5.3Atherosclerosis1.5.4Skeletal Muscle1.5.5Slow & Fast Twitch Fibres1.5.6Neurones1.5.7Speed of Transmission1.5.8Action Potentials1.5.9End of Topic Test - Neurones & Action Potentials1.5.10Synapses1.5.11Types of Synapse1.5.12Medical Application1.5.13End of Topic Test - Synapses1.5.14Chemical Brain Imbalances1.5.15Effect of Drugs on the Brain
1.6Working with Waves
1.7Waves in Communication
2Practical Scientific Procedures and Techniques
3Science Investigation Skills
3.1Scientific Processes
3.2Data Handling & Analysis
3.3Enzymes in Action
3.4Diffusion
3.5Plants & Their Environment
3.6Energy Content in Fuels
4Principles of Science II
4.1Extracting Elements
4.2Relating Properties to use of Substances
4.3Organic Chemistry
4.4Energy Changes in Industry
4.5The Circulatory System
4.5.1The Circulatory System4.5.2Blood Vessels4.5.3Blood Transfusion & the ABO Rhesus System4.5.4The Heart4.5.5The Cardiac Cycle4.5.6Cardiac Output4.5.7Coordination of Heart Action4.5.8Heart Dissection4.5.9Controlling Heart Rate4.5.10Electrocardiograms4.5.11Cardiovascular Disease4.5.12Investigating Heart Rates
4.6Ventilation & Gas Exchange
4.7Urinary System
4.9Thermal Physics
4.9.1Power & Efficiency4.9.2Work & Energy4.9.3Conservation of Energy4.9.4Pressure4.9.5First Law of Thermodynamics4.9.6Second Law of Thermodynamics4.9.7Heat Engines, Heat Pumps & Refrigerators4.9.8Non-Flow Processes4.9.9p-V Diagrams4.9.10Ideal Gases4.9.11Ideal Gases 24.9.12Thermal Energy Transfer4.9.13Thermal Energy Transfer Experiments
4.10Materials
5Contemporary Issues in Science
5.1Contemporary Issues in Science
5.2Analysing Scientific Information
Practice questions on The Periodic Table
Can you answer these? Test yourself with free interactive practice on Seneca — used by over 10 million students.
- 1The periodic table is arranged into:Fill in the list
- 2
- 3What do elements in the same group have?Multiple choice
- 4
- 5
Unlock your full potential with Seneca Premium
Unlimited access to 10,000+ open-ended exam questions
Mini-mock exams based on your study history
Unlock 800+ premium courses & e-books