Chapter 2.3: The Nature of Chemical Bonds

Question 1

Define molecule

Answer 1

• A group of atoms held together by energy in a stable association is called a molecule

Question 2

Define compound

Answer 2

• When a molecule contains atoms of more than one element, it is called a compound

Question 3

What is the basis of interaction for a covalent bond?

Answer 3

Sharing of electron pairs

Question 4

What is the basis of interaction for a ionic bond?

Answer 4

Attraction of opposite charges

Question 5

What is the basis of interaction for a hydrogen bond?

Answer 5

Sharing of H atom

Question 6

What is the basis of interaction for a hydrophobic interaction?

Answer 6

Forcing of hydrophobic portions of molecules together in presence of polar substances

Question 7

What is the basis of interaction for a Van der Waals Attraction?

Answer 7

Weak attractions between atoms due to oppositely polarized electron clouds

Question 8

Rank the following bonds from strongest to weakest: covalent bond hydrogen bond Van der Waals Attraction hydrophobic interaction ionic bond

Answer 8

1. Covalent Bond 2. Ionic Bond: 3. Hydrogen Bond 4. Hydrophobic Interaction 5. Van der Waals Attraction

Question 9

Rank the following bonds from weakest to strongest: ionic bond hydrophobic interaction covalent bond Van der Waals Attraction hydrogen bond

Answer 9

1. Van der Waals Attraction 2. Hydrophobic Interaction 3. Hydrogen Bond 4. Ionic Bond 5. Covalent Compound

Question 10

What is the strength of covalent bonds from weakest to strongest?

Answer 10

Single Bond< Double Bond< Triple Bond

Question 11

Define electronegativity

Answer 11

 Electronegativity- a property of atomic nuclei that refers to the affinity of the nuclei for valence electrons; a nucleus that is more electronegative has a greater pull on electrons than one that is less electronegative

Question 12

Define nonpolar

Answer 12

 Nonpolar- said of a covalent bond that involves equal sharing of electrons

Question 13

Define polar covalent bond

Answer 13

 Polar Covalent Bond- a covalent bond in which electrons are shared unequally due to differences in electronegativity of the atoms involved

Question 14

What is a property of atomic nuclei that refers to the affinity of the nuclei for valence electrons?

Answer 14

electronegativity

Question 15

What is said of a covalent bond that involves equal sharing of electrons?

Answer 15

nonpolar

Question 16

What is a covalent bond in which electrons are shared unequally due to differences in electronegativity of the atoms involved?

Answer 16

polar covalent com`pound

Question 17

Describe the electronegativity periodic trend

Answer 17

• In general, electronegativity increases left to right across a row of the periodic table and decreases down the column

Question 18

Define chemical reaction

Answer 18

o The formation and breaking of chemical bonds is termed a chemical reaction

Question 19

Define reactants

Answer 19

o The original molecules before the reactions starts are referred to as reactants

Question 20

Define products

Answer 20

the molecules resulting from the chemical reaction are referred to as products

Question 21

What are the 3 important factors that influence a chemical reaction?

Answer 21

1. Temperature 2. Concentration of Reactants and Products 3. Catalysts

Question 22

How does temperature affect a chemical reaction?

Answer 22

 Temperature: Heating the reactants increases the rate of reaction because the reactants collide with one another more often

Question 23

How does the concentration of reactants and products affect a chemical reaction?

Answer 23

 Concentration of Reactants and Products: Reaction proceed more quickly when more reactants are available, allowing more frequent collisions. An accumulation of products typically slows the reaction.

Question 24

How does a catalyst affect a chemical reaction?

Answer 24

 Catalyst: A catalyst is a substance that increases the rate of a reaction.

Question 25

What biological system is Ca²⁺ involved in?

Answer 25

Involved in cell signaling

Question 26

What biological system is K⁺ and Na⁺ involved in?

Answer 26

Involved in the conduction of nerve impulses