Lesson 1 - Development of the Periodic Table.pptx

History of Periodic Table

1. Development of the Periodic Table A past that cannot be forgotten.

2. HELLO! I’M... Motto: Miss Jem

3. Trace the development of the periodic table from observations based on similarities in properties of elements. List of the scientists behind in developing periodic table. - The basis they used. - The elements they discovered. Objectives: The learners should be able to:

4. Let’s do have a game! Teacher will give an instructions about the game. The content of the questions are all about from the previous lessons that already tackled by our great teachers. PRECAUTION: A group who lose the game, will face the punishment. You want it or not. DO IT. 01

5. PART OF GROWING IS ALSO LEARNING! This is where you section ends. Duplicate this set of slides as many times you need to go over all your sections.

6. Did you know? Antoine Lavoisier  made the first attempt to organize the elements of the periodic table based on the classification of their chemical properties . He organized the elements into groups of gases, non-metals, metals, and Earth elements. In June 1783, Lavoisier reacted oxygen with inflammable air, obtaining "water in a very pure state." He correctly concluded that water was not an element but a compound of oxygen and inflammable air, or hydrogen as it is now known. The idea of elements first came about in 300 B.C. The great Greek philosopher Aristotle  conceived an idea that everything on earth was made up of these elements . In ancient times, elements like gold and silver were readily accessible, however, the elements that Aristotle chose were Earth, Water, Fire, and Air.

7. FUN FACT:

8. JOHANN WOLFGANG DOBEREINER His discovery is also known as Law of Triads, he noticed that certain group of elements having similar properties seem to come in groups of three. The atomic mass of the middle element was approximately equal to the average mass of the heaviest and the lightest ones. Groups were known as Dobereiner’s triad.

9. Dobereiner’s Periodic Table 1817 (Law of Triads) The atomic mass of the middle element was approximately equal to the average mass of the heaviest and the lightest ones. Groups were known as Dobereiner’s triad. His discovery is also known as Law of Triads, he noticed that certain group of elements having similar properties seem to come in groups of three. This gave other scientists a clue that relative atomic mass was important when arranging the elements.

10. Problems Defects of his classification Dissimilar elements could not be grouped into triads A large number of similar elements could not be grouped into triads (iron, manganese, nickel, cobalt, zinc and copper). Only three triads were successfully classified

11. JOHN ALEXANDER REINA NEWLANDS (1837-1898) Reported his law of octaves (1863) Arranged the elements in their increasing atomic weights, every eight element had properties similar to each other. Has a resemblance to a musical octave

12. Newland’s Periodic Table (Law of Octaves) Reported his law of octaves Only three triads were successfully classified

13. Limitations of his Classifications Applicable only to elements with low atomic masses Fails to explain similarities of elements with higher atomic weights Newland thought only 56 elements existed (until Calcium) The Periodic table did not include inert gases

14. Julius Lothar Meyer Meyer and Mendeleev 1869 Dmitri Mendeleev Meyer established the periodicity of elements based on their physical properties (atomic volume). He was the first person to recognize the periodic trends in the properties of elements , and the graph shows the pattern he saw in the atomic volume of an element plotted against its atomic weight. Mendeleev uses the element’s chemical properties to establish the pattern. Dmitri Mendeleev created the framework that became the modern periodic table, leaving gaps for elements that were yet to be discovered.  While arranging the elements according to their atomic weight , if he found that they did not fit into the group he would rearrange them.

15. Meyer and Mendeleev Periodic Table Did you know? The father of the Periodic Table is Dmitri Mendeleev. Meyer’s PT Mendeleev’s PT Limi tations of DM’s PT More elements and isotopes were discovered The table chart of all elements was found to be inconsistent in many ways Group 8 missing in Mendeleev Periodic Table

16. HENRY MOSELEY (1914) Used atomic number rather than atomic mass in arranging the elements. Firmly established the relationship between atomic number and the charge of the atomic nucleus. Predicted the existence of the four new elements. He predicted the existence of four new elements, with 43, 61, 72, and 75 protons. These elements were discovered later by other scientists; we now call them  technetium , promethium , hafnium and rhenium .

17. 100% Editable Showcase places Henry Moseley’s Periodic Table You can use maps to show your offices or markets. Or as charts, highlighting the countries and adding your data. You can double click on the desired country and change fill color.

18. Homework: Trace the development of the Periodic Table by making a timeline. Write it in a short-sized bond paper. Do it individual. Dobereiner Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Tuesday Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Wednesday Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Thursday Friday Lorem ipsum dolor sit amet, consectetuer adipiscing elit.

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