1.2.8

Alkali Metals

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Alkali Metals

Elements found in Group 1 (found on the left-hand side of the periodic table) are referred to as the alkali metals. Their outer shell has 1 electron in it, which is usually given away in chemical reactions.

Illustrative background for Lithium (Li)Illustrative background for Lithium (Li) ?? "content

Lithium (Li)

  • Lithium has the electron structure (2,1).
  • Lithium is the least reactive of the alkali metals.
  • Lithium burns with a crimson flame when it reacts with oxygen.
  • Lithium floats on the surface of water and will release bubbles of hydrogen gas (it effervesces).
Illustrative background for Sodium (Na)Illustrative background for Sodium (Na) ?? "content

Sodium (Na)

  • Sodium has the electron structure (2,8,1).
  • Sodium is more reactive than lithium because its outer electron is less strongly attracted to the positively charged nucleus. This is because it is a greater distance from the positive charge of the atom's nucleus.
  • The metal floats on the surface of water, which releases enough heat to melt the sodium. The sodium moves quickly across the surface of the water.
  • Sodium burns with a yellow/orange flame when it reacts with oxygen.
Illustrative background for Potassium (K)Illustrative background for Potassium (K) ?? "content

Potassium (K)

  • Potassium has the electron structure (2,8,8,1).
  • Potassium is more reactive than lithium and sodium because its outer electron is least strongly attracted to the nucleus.
  • The metal floats on the surface of water, and has a similar, but more vigorous, reaction compared with sodium.
  • Potassium burns with a lilac flame when it reacts with oxygen.

Alkali Metals (Group 1) - Properties

All of the elements in Group 1 have 1 electron in their outer shell. These metals are very reactive because they easily lose the electron in their outer shell. They have similar properties and usually react in similar ways.

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Reacting with water

  • The metal floats on the surface and melts to create a metal hydroxide (e.g. lithium hydroxide).
  • When they react with water, the energy released is enough to melt the metal.
Illustrative background for Reacting with chlorineIllustrative background for Reacting with chlorine ?? "content

Reacting with chlorine

  • A metal chloride is formed (e.g. sodium chloride), which dissolves in water to give a colourless solution.
Illustrative background for Reacting with oxygenIllustrative background for Reacting with oxygen ?? "content

Reacting with oxygen

  • Rapidly turns from silvery shiny to dull as a metal oxide (e.g. potassium oxide) is produced.

Jump to other topics

1Principles of Science I

1.1Structure & Bonding

1.2Properties of Substances

1.3Cell Structure & Function

1.4Cell Specialisation

1.5Tissue Structure & Function

1.6Working with Waves

1.7Waves in Communication

2Practical Scientific Procedures and Techniques

3Science Investigation Skills

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

4.6Ventilation & Gas Exchange

4.7Urinary System

4.8Cell Transport

4.9Thermal Physics

4.10Materials

4.11Fluids

5Contemporary Issues in Science

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