The Periodic Table And Trends

Learn it by playing

Answer these questions to earn energy, then fish and explore. No account needed.

For teachers: ready-to-use lesson slides, revision notes, diagrams for The Periodic Table And Trends (Co-ordinated Sciences (Double Award) [CIE], Chemistry) — use them in your lesson, or run the topic as a live class game.

Notes

The Periodic Table

Elements are arranged in order of **increasing atomic number**.
Vertical columns are called **groups**; horizontal rows are called **periods**.
The **period number** indicates the number of electron shells an atom has.
The **group number** (1–7, plus Group 0) indicates the number of outer-shell electrons.
Group number helps determine the charge of ions: metals lose electrons (positive ions), non-metals gain electrons (negative ions).
For example, Group 1 metals form 1+ ions; Group 7 non-metals form 1− ions.

Periodic Trends in Metallic Character

**Metallic character** decreases from left to right across a period.
Metallic character increases down a group.
Metals are on the left of the Periodic Table; non-metals on the right.
Elements between metals and non-metals are called **metalloids** or semi-metals.
Metals have 1–3 outer electrons, form metallic bonds, conduct electricity, and produce basic oxides.
Non-metals have 4–7 outer electrons, form covalent bonds, are poor conductors, and produce acidic oxides.

Electronic Configuration and Position

**Electronic configuration** (e.g., 2,4 for carbon) shows the number of electrons in each shell.
The number of notations (shells) equals the **period number**.
The last notation (outer electrons) equals the **group number**.
Elements in the same group have the same number of outer electrons and similar chemical properties.
For example, lithium (2,1) and sodium (2,8,1) are both in Group 1 and react similarly.

Trends in Reactivity: Group 1 Metals (Extended)

**Reactivity of Group 1 metals increases down the group**.
Lithium reacts slowly with water, fizzing and moving on the surface.
Sodium reacts more vigorously, moving rapidly and dissolving quickly.
Potassium reacts even more vigorously, burning with a lilac flame.
Rubidium and caesium react explosively; francium is too reactive to predict.
The trend can be used to predict properties of other elements in the group.

Bohr model of sodium atom (electronic configuration 2,8,1) showing its position in Period 3, Group 1.

Practice questions

Free preview — 8 of 12 questions. Sign up to see them all.

1.Elements are arranged on the Periodic Table in order of increasing
Easy
- Aatomic mass
- Batomic number
- Cnumber of neutrons
- Dmass number
2.What is the name given to the vertical columns in the Periodic Table?
Easy
3.What is the name given to the horizontal rows in the Periodic Table?
Easy
4.How many electrons are in the outer shell of an element in Group 6?
Easy
- A7
- B6
- C5
- D8
5.Elements in the same group have similar chemical properties because they have the same number of outer shell electrons.
Easy
True or false?
6.Complete the sentence.
Medium
The metallic character of elements $____ as$ you move across a period from left to right.
7.Match each element to its electronic configuration.
Medium
- Sodium
- Chlorine
- Carbon
- 2,4
- 2,8,1
- 2,8,7
8.Arrange these Group 1 metals in order of increasing reactivity with water (least reactive first).
Medium
- sodium
- lithium
- potassium

Slides

The Periodic Table

Elements are arranged in order of increasing atomic number.
Vertical columns are called groups; horizontal rows are called periods.
The group number tells you how many outer electrons an atom has.
The period number tells you how many electron shells an atom has.

What does the period number of an element represent?

The number of outer electrons
The number of electron shells
The atomic mass
The group number

Groups and Ion Charges

Metals in Group 1 lose 1 electron to form 1+ ions.
Metals in Group 2 lose 2 electrons to form 2+ ions.
Non-metals in Group 6 gain 2 electrons to form 2− ions.
Non-metals in Group 7 gain 1 electron to form 1− ions.

A magnesium atom is in Group 2, so it will lose ____ electrons to form $a ____ ion$ .

Metallic Character Trend

Metallic character decreases from left to right across a period.
Metallic character increases down a group.
Metals are on the left; non-metals on the right.
Metalloids lie between metals and non-metals.

Which of these are true about metallic character?

Metallic character increases from left to right across a period.
Metallic character increases down a group.
Non-metals are found on the right-hand side of the Periodic Table.

Properties of Metals and Non-Metals

Metals: 1–3 outer electrons, metallic bonding, good conductors, basic oxides.
Non-metals: 4–7 outer electrons, covalent bonding, poor conductors, acidic oxides.
Metals are malleable with high melting points; non-metals are brittle with low melting points.

Which property is typical of non-metals?

Good electrical conductivity
Basic oxides
Brittle
Malleable

Electronic Configuration and Position

Electronic configuration shows the number of occupied shells (period) and outer electrons (group).
Example: Chlorine has configuration 2,8,7 → Period 3, Group 7.
Elements in the same group have the same number of outer electrons and similar chemical properties.

An element with electronic configuration 2,8,2 is in Period $____ and$ Group ____.

Trends in Group 1 Reactivity

Group 1 metals (alkali metals) react with water to produce hydroxide and hydrogen.
Reactivity increases down the group: lithium reacts slowly, sodium more vigorously, potassium burns with a lilac flame.
Trend can be used to predict that rubidium and caesium react even more vigorously.

Which Group 1 metal reacts most vigorously with water?

Lithium
Sodium
Potassium
Francium

Identifying Trends from Data

To identify a trend, arrange elements in order of their position in the group.
Look for patterns in properties such as reactivity, melting point, or atomic radius.
For Group 1, reactivity increases down the group; for Group 7, reactivity decreases down the group.

Which statements about Group 1 metals are correct?

Lithium is more reactive than sodium.
Reactivity increases down the group.
Potassium reacts with water to produce hydrogen gas.

Flashcards

How are elements arranged on the Periodic Table?

In order of increasing atomic number, in rows called periods and columns called groups.

What does the period number tell you about an atom?

The number of electron shells an atom has. For example, Period 2 elements have two shells.

What does the group number tell you about an atom?

The number of outer (valence) electrons. For example, Group 4 elements have 4 outer electrons.

What ion charge does a Group 1 metal form?

1+ (it loses one electron).

What ion charge does a Group 2 metal form?

2+ (it loses two electrons).

What ion charge does a Group 7 non-metal form?

1− (it gains one electron).

What ion charge does a Group 6 non-metal form?

2− (it gains two electrons).

How does metallic character change across a period?

It decreases from left to right.

How does metallic character change down a group?

It increases.

Where are metals and non-metals located on the Periodic Table?

Metals on the left, non-metals on the right, with metalloids in between.

What type of oxide do metals typically form?

Basic oxides.

What type of oxide do non-metals typically form?

Acidic oxides.

How does the electronic configuration relate to period and group?

The number of notations equals the period; the last notation equals the group number.

Why do elements in the same group have similar chemical properties?

They have the same number of outer electrons.

What is the trend in reactivity of Group 1 metals down the group?

Reactivity increases down the group.

Write the word equation for the reaction of lithium with water.

lithium + water → lithium hydroxide + hydrogen

Write the balanced chemical equation for sodium reacting with water.

2Na(s) + 2H₂O(l) → 2NaOH(aq) + H₂(g)

What observations indicate that potassium reacts more vigorously with water than sodium?

Burns with a lilac flame, moves very rapidly, dissolves very quickly.

What is the electronic configuration of lithium?

2,1

What is the electronic configuration of sodium?

2,8,1

What is the electronic configuration of potassium?

2,8,8,1

What is the electronic configuration of chlorine?

2,8,7

Which element in Group 1 is the least reactive?

Lithium (at the top).

Which element in Group 1 is predicted to be the most reactive?

Francium (at the bottom).

Unlock all 12 questions, slides, flashcards & more

Create a free account to see every question, the slides, flashcards and revision notes for this topic.

Past papers

Past-paper practice for this topic is coming soon.

🗂️ Coming soon