Chapter 13 Holt The Periodic Table Chapter Highlights

Chapter 13 Holt The Periodic Table

Chapter Highlights • Vocabulary

• Periodic - having a regular, repeating pattern

• Periodic Law - a law that states that the chemical and physical properties of elements are periodic functions of their atomic number

• Period - a horizontal row of elements on the periodic table • Example: Period 2 • Li Be B C N O F Ne

• Group - a column of elements on the periodic table that have some similarity amongst them • For example: Group 18 • He • Ne • Ar • Kr

• Alkali metals - the elements in the Group 1 of the periodic table. They are the most reactive metals, and their atoms have 1 electron in their outer level • Li Na K Rb Cs Fr

• Alkaline-earth metals - the elements in Group 2 of the periodic table. They are reactive metals but less reactive than Group 1 alkali metals. Their atoms have 2 electrons in their outer level. • Be Mg Ca Sr Ba Ra

• Halogens - the elements in Group 17 of the periodic table. They are very reactive nonmetals, and their atoms have 7 electrons in their outer level. • F Cl Br I At

• Noble gases - the un-reactive elements in Group 18 of the periodic table. Their atoms have 8 electrons in their outer level (except helium, which has 2 electrons, and a full innermost level). • He Ne Ar Kr Xe Rn

Chapter Review • Pages 344 -345

• 1) Elements in the same vertical column in the periodic table belong to the same Group.

• 2. Elements in the same horizontal row in the periodic table belong to the same period.

• 3. The most reactive metals are alkali metals

• 4. Elements that are un-reactive are called noble gases

• 5. An elements that is a very active gas is most likely a member of the • C) halogens

• 6. The statement that is true is • B) Alkali metals are Group 1 elements

• 7. The statement about the periodic table that is false is : • C) The elements at the far left of the periodic table are nonmetals

• 8. One property of most nonmetals is that they are • B) poor conductors of electricity

• 9. A true statement about elements is • C) each elements has a unique atomic number

• 10. This is NOT found on the periodic table • C) the density of each element

• 11. Why was Mendeleev’s periodic table useful? • Mendeleev’s periodic table allowed scientists to predict properties of elements that had not been found.

• 12. How is Moseley’s basis for arranging the elements different from Mendeleev’s? • Moseley arranged elements by increasing atomic number. • Mendeleev arranged elements by atomic mass.

• 13. How is the periodic table like a calendar? • Both are periodic. The Periodic table has repeating properties of elements; the calendar has repeating days and months.

• 14. Describe the location of the metals, metalloids, and nonmetals on the periodic table. • Metals - located left of zig-zig line • Metaloids - border the zig-zig line • Nonmetals - right of the zig-zag line.

• 15 - Concept mapping - on the board

• 16. An element with 115 protons in its nucleus synthesizes, it will be a metal, it will be located below the bismuth to the left of the zig-zag.

• 17. Mendeleev could only make predictions about elements where there were clear gaps in his table. Because no noble gases were known at the time, there were no obvious gaps in the table and no way he could have know an entire column was missing.

• 18. I would tell my classmates that he didn’t find sodium. Sodium is very reactive and cannot be found uncombined in nature. It would react with oxygen and water in the air and form a compound.

• 19. Identity of elements: • A) Calcium - very reactive metal, properties similar to magnesium, is in same period as bromine. • B) Carbon - one nonmetal in same group as lead • C) Potassium - most reactive metal in the group and cannot be found uncombined in nature. Each atom contains 19 protons.

• 20. Using chart on page 345. • A) alkali metals 5. 4 % (sodium & potassium) • B) alkaline-earth metals: 5. 6 % (magnesium & calcium)

• 21. Periodic properties are the order of the shapes and the number of lines inside the shapes. The properties shared in a group are the shape and the color of lines inside the shape. • Figure between 3/11.