1. QOTD  What are the three groups that elements are classified in on the periodic table?

2. Elements, Compounds, and Mixtures Mr. Dunnum Physical Science

3. Elements Element- is a pure substance that cannot be separated into simpler substances by chemical or physical means Pure substance- is a substance in which there is one type of particle

4. Elements Each element has its own unique set of properties that allows you to identify it. You can identify the elements by melting point, density,color, hardness, and sometimes texture

5. Elements Elements are classified and grouped according to their shared properties Metal- are shiny good conductors Nonmetals- dull and poor conductors Metalloids- called semiconductors, have properties of both metals and nonmetals

6. Elements to know LithiumLi SodiumNa PotassiumK RubidiumRb CesiumCs FranciumFr

7. The Periodic Table The periodic table arranges and displays all known elements in an orderly way Each element has its own Chemical symbol

8. Who discovered the Periodic Table?  In science there are always several scientist who contribute to new discoveries, but the one who received credit for it is Dmitri Mendeleev

9. Dmitri Mendeleev  Mendeleev first arranged the periodic table in ascending atomic weights and similar properties.  He also left room for the unknown elements and noble gases  After several years of research and many different forms the periodic table, we now have the periodic table we all know

10. Periodic Table

11. Periodic table Cl is the symbol for chlorine. The top number is the element’s atomic number. Tells how many protons in the nucleus The bottom number is the atomic mass which tells us the average mass of the atom

12. Isotopes Although the number of protons changes from element to element, every atom of the same element has the same number of protons. However, the number of neutrons can vary even for one element. These are called isotopes (I suh tohps), which are atoms of the same element that have different numbers of neutrons.

13. Isotopes An atom’s mass number is the number of protons plus the number of neutrons it contains.

14. Compounds A compound is formed when two or more elements are joined chemically. Once these elements are formed they become a whole new substance Just like elements compounds have their own set of properties Ex. H20 Ex. NaCl Ex. C 6 H 6

15. Compound

16. Compounds Breakdown Compounds can be broken down into simpler substances The only way compounds can be broken down is through chemical change. In our world Proteins-build muscle and helps digest food Carbon dioxide in respiration Industry Medicines, food preservatives, and synthetic fabrics

17. Elements to know BerylliumBe MagnesiumMg CalciumCa StrontiumSr BariumBa RadiumRa