ch.2 The Nature of Chemical Bonds

Question 1

molecule

Answer 1

group of atoms held together by energy in a stable associated

Question 2

compound

Answer 2

when a molecule contains atoms of more than one element

Question 3

chemical bonds– ionic and covalent

Answer 3

bonds can result when atoms with opposite charges attract each other (ionic bonds), when two atoms share one or more pairs of electrons (covalent bonds), or when atoms interact in other ways.

Question 4

covalent bond

Answer 4

sharing of electron pairs

Question 5

ionic bond

Answer 5

attraction of opposite charges

Question 6

hydrogen bond

Answer 6

sharing of H atom

Question 7

hydrophobic interaction

Answer 7

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

Question 8

van der Waals attraction

Answer 8

weak attractions between atoms due to oppositely polarized electron clouds.

Question 9

covalent bonds: how they form and more

Answer 9

-form when two atoms share one or more paris of valence electrons.

Question 10

A molecule, like the example with two hydrogen atoms, is stable for three reasons

Answer 10

1. it has no net charge
2. octet rule is satisfied
3. no unpaired electrons

Question 11

electronegativity

Answer 11

-increases left to right and decreases down the column. (upper right corner have the highest electronegativity)

Question 12

non polar

Answer 12

for bonds between identical atoms, ex, between two hydrogen atoms, the affinity for electrons is the same; they are non polar.

Question 13

polar covalent bonds

Answer 13

-unequal distribution results in regions of partial negative charge near the more electronegative atom, and regions of partial positive charge near the less electronegative atom.

Question 14

relative electronegativity for OCHN atoms

Answer 14

O=3.5
C=2.5
H=2.1
N=3.0

Question 15

the extent to which chemical reactions occur is influence by 3 important factors

Answer 15

1. tempurature
2. concentration of reactants and products (more reactants allow more frequent collisions, slows down the reaction, and may speed the reaction in the reverse direction).
3. Catalysts (a substance that increases the rate of a reaction; enzymes in living systems)