Chapter 6 Section 1

1. Chapter 6 Section 1 The Periodic Table and Periodic Law

2. Development of the Periodic Table • Antoine Lavoisier (1743 – 1794): compiled a list of all the known elements in the early 1700’s • List contained 33 elements

3. Development of the Periodic Table • In 1864, English chemist John Newlands proposed an organizational scheme for the elements. • He noticed that when the elements were arranged by increasing atomic mass, their properties repeated every eighth element

4. Development of the Periodic Table • In 1869, Lothar Meyer and Dmitri Mendeleev each demonstrated a connection between mass and elemental properties. • Mendeleev is given credit for the Periodic Table because he published his first. • Mendeleev’s table arranged the elements by increasing atomic mass into columns with similar properties.

5. Development of the Periodic Table • Mendeleev’s table became widely used because he predicted the existence and properties of undiscovered elements

6. The Development of the Periodic Table • Mendeleev’s table was not completely correct though. • In some instances, ordering elements by mass created disorder among elements with like properties.

7. The Development of the Periodic Table • Moseley arranged the periodic table in order of increasing atomic number. • The statement that there is a periodic repetition of chemical and physical properties of the elements when they are arranged by increasing atomic number is called the periodic law.

8. The Modern Periodic Table • Consists of boxes containing an element name, symbol, atomic number, and atomic mass. • The columns of the periodic table are called groups. • The rows of the periodic table are called periods.

9. The Modern Periodic Table Representative Elements Transition Elements

10. The Modern Periodic Table

11. Metals • Shiny when smooth • Solid at room temperature • Good conductor of heat and electricity • Malleable – can be hammered into sheets • Ductile – can be drawn into wires

12. Metals • Group 1: Alkali Metals (except hydrogen) • Extremely reactive • Often exist as compounds with other elements • Li, Na, K, Rb, Cs, Fr

13. Metals • Group 2: Alkaline Earth Metals • Groups 3 – 12: Transition Elements • Inner Transition Metals • Lanthanide series (begins with element 58) • Actinide series (begins with element 90)

14. Non-Metals • Occupy the upper right side of the PTE. • Generally gases or brittle, dull-looking solids • Poor conductors of heat and electricity • Only non-metal that is a liquid at room temperature is Bromine

15. Non-Metals • Group 7 (17): Halogens • Group 8 (18): Noble Gases

16. Metalloids • Contained in the stair step between the metals and non-metals • Also known as semi-metals • Have physical and chemical properties of both metals and non-metals