Group 18 Elements
Chapter Name : The P- Block Elements |
Sub Topic Code : 102_12_07_23_01 |
Topic Name : Group 18 Elements |
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Sub Topic Name : Occurrence |
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Introduction
• Noble gases compose the group 18 elements Ar, Ne, Xe, Krypton. • All these are gases and chemically unreactive. • They form very few compounds. • Because of this they are termed noble gases. • All the noble gases except radon occur in the atmosphere. • Their atmospheric abundance in dry air is ~ 1% by volume of which argon is the major constituent. • Helium and sometimes neon are found in minerals of radioactive origin e.g. pitchblende, monazite, cleveite. • The main commercial source of helium is natural gas. • Xenon and radon are the rarest elements of the group. • Radon is obtained as a decay product of 226Ra.
Pre-Requisites:
Periodic table, elements,
Activity:
Gas balloons have helium in them.
Real Life Question:
Which gas do balloons have?
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| group | Group is the vertical column on the periodic table which contains elements having the similar properties. |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| Neon | Neon is used to make lights. |
Places to visit :
Playground, street signs.
Practical examples around us
| Examples | Explainations |
|---|---|
| Street signs | Some street signs glow due to neon. |
What you learn in Theory:
• Noble gases compose the group 18 elements Ar, Ne, Xe, Krypton. • All these are gases and chemically unreactive. • They form very few compounds. • Because of this they are termed noble gases. • All the noble gases except radon occur in the atmosphere. • Their atmospheric abundance in dry air is ~ 1% by volume of which argon is the major constituent. • Helium and sometimes neon are found in minerals of radioactive origin e.g. pitchblende, monazite, cleveite. • The main commercial source of helium is natural gas. • Xenon and radon are the rarest elements of the group. Radon is obtained as a decay product of 226Ra.
What you learn in Practice:
• Noble gases compose the group 18 elements Ar, Ne, Xe, Krypton. • All these are gases and chemically unreactive. • They form very few compounds. • Because of this they are termed noble gases. • All the noble gases except radon occur in the atmosphere. • Their atmospheric abundance in dry air is ~ 1% by volume of which argon is the major constituent. • Helium and sometimes neon are found in minerals of radioactive origin e.g. pitchblende, monazite, cleveite. • The main commercial source of helium is natural gas. • Xenon and radon are the rarest elements of the group. Radon is obtained as a decay product of 226Ra.