Page 47 - Chemistry_Form_2

Chemistry
for Secondary Schools

contribute to this application?
5. How do the electronic configurations of Group I elements determine their
reactivity?
6. Compare the solubility of Group II hydroxides in water. How does this trend
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change down the group?
7. Calcium is essential in human bones and teeth. How do its chemical properties
contribute to this biological role?
8. Why are Group II elements less reactive than Group I elements? Use their
electronic configurations to support your answer.
9. Why do the reactivities of Group VII elements decrease down the group?
Use fluorine and iodine as examples.

10. Explore the changes in physical states observed across Group VII elements.
What trend is observed within the group?

Chapter summary

1. The periodic table of elements is a method of displaying chemical elements
in a table format. It was developed after several modifications to the
Mendeleev’s periodic table.

2. Mendeleev’s Periodic Law states that the properties of elements are periodic
functions of their relative atomic masses.

3. The Modern Periodic Law states that the properties of elements change
systematically according to their atomic numbers.

4. Periodicity refers to the regular periodic changes of properties of elements
due to changes in atomic numbers.

5. Elements with the same number of electrons in their outermost shells
belong to the same group.

6. The group number signifies the number of electrons in the outermost shell
of an element.

7. Elements with the same number of shells belong to the same period.

8. The electronic configuration of an element entails the electronic
arrangements in the shell(s), number of shells, and the group to which the
element belongs.

40 Student’s Book Form Two

01/08/2025 11:20:53
CHEMISTRY FORM TWO NEW 2025 DUMMY.indd 40
CHEMISTRY FORM TWO NEW 2025 DUMMY.indd 40 01/08/2025 11:20:53