Holt Chapter 14

Chapter Review

Using Vocabulary

• 1. The force of attraction that holds two atoms together is a chemical bond.

• 2. Charged particles that form when atoms transfer electrons are ions.

• 3. The force of attraction between the nuclei of atoms and shared electrons is a covalent bond.

• 4. Electrons free to move throughout a material are associated with a metallic bond.

• Shared electrons are associated with a covalent bond.

Understanding Concepts

• 6. Which element has a full outermost energy level containing only 2 electrons?

• a) oxygen b) hydrogen c) fluorine

• d) helium

• Answer: d) Helium

• 7. Which (of the following) describes what happens when an atom becomes an ion with a 2- charge?

• Answer: c) the atom gains 2 electrons

• 8. The properties of ductility and malleability are associated with which type of bonds?

• a) ionic b) covalent c) metallic d) none of the above

• Answer: c) metallic

• 9. In which area of the periodic table do you find elements whose atoms easily gain electrons?

• Answer: c) on the right side

• 10. What type of element tends to lose electrons when it forms bonds?

• A) metal b) metalloid c) nonmetal d) noble gas

• Answer: a) metals

• 11. Which pair of atoms can form an ionic bond?

• Answer:

• b) potassium (K) and fluorine (F)

Short Answers

• 12. List two properties of covalent compounds.

• Answers could include:

• - a low melting point,

• - a low boiling point,

• - brittle when solid at room temp.

• 13. Explain why an iron ion is attracted to a sulfide ion but NOT to a zinc ion?

• Answer: iron and zinc are metals that tend to lose electrons , thus becoming positively charged. They would repel each other.

• Sulfide ion is negatively charge sulfur atom that gained electron, so is attracted to a positively charge atom such as iron

• 14. Using knowledge of valence electrons, explain why carbon is an element in so many different molecules.

• Carbon has 4 valence electrons, therefore can have 4 bonds, including other carbon atoms. This is the most bonding possibilities. Usually atoms with less than 4 valence electrons give up electrons, and may only have one bond.

• 15. Three types of bonds:

• Ionic - lose/gain electrons

• Covalent - share electrons

• Metallic - electrons can move between ions within a metal

Concept map

• 16. This was put on the board

Critical Thinking

• 17. Types of bonding of these pairs:

• A) zinc + zinc = metallic

• B) oxygen + nitrogen = covalent

• C) phosphorus and oxygen = covalent

• D) magnesium and chlorine = ionic

• 18. Dots & bonds

• A) sulfur (S); 6 dots, 2 bonds

• B) nitrogen (N); 5 dots, 3

• C) neon (Ne); 8 dots, 0 bonds

• D) iodine (I); 7 dots, 1 bond

• E) silicon (Si); 4 dots, 4 bonds

• 19. What type of bond does the picture of a hammer is hitting a white, solid object with little parts appearing on the table represent.?

• Answer: The substance is brittle, and is breaking into tiny pieces, therefore is an ionic bond.

Math in Science

• 20.Electrons gained/loss and charge

• Answers:

• A) calcium (Ca); lose 2 e-; 2 +

• B) phosphorus (P); gain 3e-; 3 -

• C) bromine (Br); gain 1e-; 1-

• D) sulfur (S); gain 2e-; 2 -

Interpreting Graphics

• 21. The metal band near the eraser is the part of the pencil where metallic bonds are formed.

• 22. Molecules with covalent bonds in a pencil include:

• - graphite

• - wood

• - eraser

• 23. Two differences between the properties of the parts of the pencil are:

• Answer: The metallically bonded part of the pencil is shiny, can be bent without breaking, and is hard in texture;

• The covalently bonded parts are not shiny, will break when bent, and are softer. Example: eraser, graphite, wood

• The End