2. General Informations Name of the teacher : Jennifer. M. Job Subject :Chemistry Topic : Mendeleev’s periodic law, Moseley’s periodic law and Modern periodic table and details of the element Lithium Unit :Periodic table and Chemical Bond l

3. LEARNING OUTCOMES Remember : a) The pupil recalls group and period b) The pupil recognizes Mendeleev’s periodic law and Moseley’s periodic law. Understand : c) The pupil compares Mendeleev’s periodic law and Moseley’s periodic law. Apply : d)The pupil applies the periodic law in new and unfamiliar situations. Analyze : e) The pupil focusses the ideas-Mendeleev’s periodic law and Moseley’s law, atomic number, atomic mass, electron distribution etc. Evaluate : f) The pupil judges the differences between periodic law of Mendeleev and Moseley. Create : g) The pupil generate examples for elements to find out the details about them from the periodic table.

4. INTRODUCTION New discoveries and the knowledge gained about the structure of the atoms paved the way for a detailed study of the properties of elements. The studies conducted by moseley regarding the properties of the elements related to their position in the periodic table, finally proved that the basic properties of elements depend on their atomic number and note on their atomic masses

5. CONTENT The modern periodic table, which we now use, is the improved version of Mendeleev’s periodic table. The properties of elements depend on their atomic numbers.

6. Mendeleev’s Periodic Law Properties of elements depends on their atomic masses. When the elements are arranged in the ascending order of their atomic masses it is seen that their properties are repeated at specific intervals.

7. Moseley modified Mendeleev’s periodic law accordingly When elements are arranged in the ascending order of their atomic numbers there is a repetition of their properties at fixed intervals. Properties of elements depends on their atomic numbers.

8. One Portion Of The Periodic Table 1 H Hydrogen 1 2 He Helium 2 3 Li Lithium 2, 1 4 Be Beryllium 2, 2 5 B Boron 2, 3 6 C Carbon 2, 4 7 N Nitrogen 2, 5 8 O Oxygen 2, 6 9 F Fluorine 2, 7 10 Ne Neon 2, 8 11 Na Sodium 2, 8, 1 12 Mg Magnesium 2, 8, 2 13 Al Aluminium 2, 8, 3 14 Si Silicon 2, 8, 4 15 P Phosphorous 2, 8, 5 16 S Sulphur 2, 8, 6 17 Cl Chlorine 2, 8, 7 18 Ar Argon 2, 8, 8 19 K Potassium 2, 8, 8, 1 20 Ca Calcium 2, 8, 8, 2  There are 7 periods.  There are 18 groups.

9. The Details of the Element - Lithium Atomic number3 SymbolLi NameLithium Atomic mass4 Electron distribution2, 1

10. FOLLOW-UP ACTIVITY  Write the details of elements of elements Oxygen (O) and Carbon (C).

11. CONCLUSION From this we came to a conclusion that the modern periodic table, which we now use, is the improved version of Mendeleev’s periodic table. From this we came to a conclusion that the modern periodic table, which we now use, is the improved version of Mendeleev’s periodic table.