Page 129 - Chemistry ICSE Class IX

CHAPTER 5

The Periodic Table

TOPICS COVERED

ƒ Reasons for the classification ƒ Periodicity in properties ƒ Chemical reactivity
of elements ƒ Atomic number ƒ Nature of oxides
ƒ Earlier attempts for the ƒ Atomic size ƒ Uses of modern periodic
periodic classification of ƒ Valence electrons table
elements ƒ Valency ƒ Alkali metals (Group 1)
ƒ Mendeleev's periodic law ƒ Tendency to lose electrons ƒ Alkaline earth metals
ƒ Mendeleev's periodic table ƒ Tendency to attract/gain (Group 2)
ƒ Modern periodic law electrons ƒ Halogens (Group 17)
ƒ Modern long form periodic ƒ Metallic and nonmetallic ƒ Zero group (Group 18)
table characters

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BOXED FEATURES future developments in ASSIGNMENTS testing your learning
science

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ILLUSTRATIVE understanding for the LET US ANSWER SOME your conceptual
QUESTIONS topics studied MORE QUESTIONS understanding

Helps you to reflect back
LET US SAY IT AGAIN on what you have learned