Searching For an Organizing Principle 6.1 Searching For an Organizing Principle Searching For an Organizing Principle How did chemists begin to organize the known elements? Chemists used the ________________ of elements to sort them into groups.

Searching For an Organizing Principle 6.1 Searching For an Organizing Principle Chlorine, bromine, and iodine have very similar ______________ ______________. Chlorine, bromine, and iodine have very similar chemical properties. The numbers shown are the average atomic masses for these elements.

Mendeleev’s Periodic Table 6.1 Mendeleev’s Periodic Table Mendeleev’s Periodic Table How did Mendeleev organize his periodic table?

Mendeleev’s Periodic Table 6.1 Mendeleev’s Periodic Table Mendeleev arranged the elements in his periodic table in order of ______________ ______________ ______________. The periodic table can be used to ______________ the properties of undiscovered elements.

The Periodic Law How is the modern periodic table organized? 6.1

6.1 The Periodic Law In the modern periodic table, ______________ are arranged in order of ______________ ______________ ______________. In the modern periodic table, the elements are arranged in order of increasing atomic number. Interpreting Diagrams How many elements are there in the second period?

6.1 The Periodic Law The periodic law: When elements are arranged in order of increasing atomic number, there is a periodic ______________ of their ______________ and ______________ properties. The ______________ of the elements within a period ______________ as you move ______________ a period from left to right. The pattern of properties within a period ______________ as you move from one period to the next.

Metals, Nonmetals, and Metalloids 6.1 Metals, Nonmetals, and Metalloids Metals, Nonmetals, and Metalloids What are three broad classes of elements? Three classes of elements are ______________ , ______________ , and ______________ . Across a period, the properties of elements become ______________ metallic and ______________ ______________.

Metals, Nonmetals, and Metalloids 6.1 Metals, Nonmetals, and Metalloids Metals ______________ are good ______________ of ______________ and ______________ ______________ . 80% of elements are ______________. Metals have a high ______________ , are ______________ , and are ______________.

Metals, Nonmetals, and Metalloids 6.1 Metals, Nonmetals, and Metalloids Nonmetals In general, ______________ are ______________ ______________ of heat and electric current. Most ______________ are ______________ at room temperature. A few nonmetals are solids, such as sulfur and phosphorus. One nonmetal, ______________ , is a dark- red ______________.

Metals, Nonmetals, and Metalloids 6.1 Metals, Nonmetals, and Metalloids Metalloids A ______________ generally has properties that are ______________ to those of both metals and nonmetals. The ______________ of a metalloid can be controlled by ______________ ______________.

Section Assessment Questions 1 Section Assessment Questions 1. The modern periodic table has elements arranged in order of Mendeleev arranged the elements in his periodic table in order of increasing Which one of the following is NOT a general property of metals?