1. Ch. 4 – The Periodic Table

2. Today’s Assignment Read pgs. 104-105 and make your own notes. Do Activity 4.3 on page 108-109. Do all parts of the procedure and hand in by the end of class. If you finish early do Understanding Concepts (pg. 109) ques. 1-4 & 6.

3. Groups of Elements The periodic table is arranged so that elements with similar properties are in groups. There are groups with specific names on the table. These groups are named because the elements in these groups have extraordinary properties. Video

4. A Family is also called a Group.

5. based on their atomic numbers.

6. Groups or Families Columns of elements are called groups or families. Elements in each family have similar but not identical properties. For example, lithium (Li), sodium (Na), potassium (K), and other members of family IA are all soft, white, shiny metals. All elements in a family have the same number of electrons in their outer orbital. Each horizontal row of elements is called a period. The elements in a period are not alike in properties. In fact, the properties change greatly across even given row. The first element in a period is always an extremely active solid. The last element in a period, is always an inactive gas. The period tells us how many orbitals the element has. Periods

7. Noble Gases Noble Gases are colorless gases that are extremely un- reactive. One important property of the noble gases is their inactivity. They are inactive because their outermost energy level is full. Because they do not readily combine with other elements to form compounds, the noble gases are called inert. The family of noble gases includes helium, neon, argon, krypton, xenon, and radon. All the noble gases are found in small amounts in the earth's atmosphere.

8. Alkali Metals These metals are highly reactive and readily form compounds with other elements. Most commonly H, O, Cl, F, Br, I. The reactivity of alkali metals is explained by their structure. These metals have only one electron in their outer orbital. They will readily lose this electron to become a stable atom. The alkali metals (group 1A) are located in the far left column of the periodic table.

9. Halogens They make very useful compounds such as iodized table salt, chlorine in drinking water, sodium fluoride in toothpaste, etc. The reactivity of halogens is explained by their structure. These non metals need only 1 electron to fill their outer orbital. They will readily gain this electron to become a stable atom. Group VII A Include F, Cl, Br, I, At Next to the noble gases These are the most reactive non metals. They almost always appear naturally as compounds (Cl 2, Br 2, etc.)

10. A Group of One Hydrogen is a unique element. It has only 1 electron. Therefore it has only one orbital (How many electrons can this orbital hold?) It can react as both a metal and a non metal. It can either lose or gain 1 electron to become a stable atom. Most of the Earth’s hydrogen exists in compounds due to it’s high reactivity.

11. Metalloids Metalloids (metal-like) have properties of both metals and non-metals. They are solids that can be shiny or dull. They conduct heat and electricity better than non-metals but not as well as metals. They are brittle and not ductile

12. Metalloids have some characteristics of both metals and nonmetals. They are B, Si, Ge, As, Sb, Te, Po. How to tell metals from nonmetals: B Al Si Ge As Sb Te Po At These are the purple elements on the periodic table in your textbook.

13. Assignment Read pgs. 110 – 113 Understanding Concepts pg. 113; answer questions 1 – 10.