Basic Chemistry and The Properties Of Water

Elements and Compounds

• Matter is made up of elements • An element is a substance that cannot

be broken down to other substances by chemical reactions

• A compound is a substance consisting of two or more elements in a fixed ratio

• A compound has characteristics different from those of its elements

© 2011 Pearson Education, Inc.

Table 2.1

Figure 2.5

Cloud of negativecharge (2 electrons)

Electrons

Nucleus

(a) (b)

Figure 2.8

A ball bouncing down a flightof stairs provides an analogyfor energy levels of electrons.

Third shell (highest energylevel in this model)

Second shell (higherenergy level)

First shell (lowest energylevel)

Atomic nucleus

Energyabsorbed

Energy lost

(b)

(a)

Figure 2.12a

(a) Hydrogen (H2)

Name andMolecularFormula

ElectronDistribution

Diagram

Lewis DotStructure and

StructuralFormula

Space-FillingModel

Figure 2.12b

(b) Oxygen (O2)

Name andMolecularFormula

ElectronDistribution

Diagram

Lewis DotStructure and

StructuralFormula

Space-FillingModel

Figure 2.12c

Name andMolecularFormula

ElectronDistribution

Diagram

Lewis DotStructure and

StructuralFormula

Space-FillingModel

(c) Water (H2O)

Figure 2.12d

(d) Methane (CH4)

Name andMolecularFormula

ElectronDistribution

Diagram

Lewis DotStructure and

StructuralFormula

Space-FillingModel

Figure 2.13

H H

H2O+ +

–

O

Figure 2.14-2

+ –

NaSodium atom

ClChlorine atom

Na+

Sodium ion(a cation)

Cl–

Chloride ion(an anion)

Sodium chloride (NaCl)

Figure 2.15

Na+

Cl–

Figure 2.16

Water (H2O)

Ammonia (NH3)

Hydrogen bond

–

–

+

+

+

+

+

Figure 2.18

Natural endorphin

Morphine

Carbon

Hydrogen

Nitrogen

Sulfur

Oxygen

(a) Structures of endorphin and morphine

(b) Binding to endorphin receptors

Brain cell

MorphineNaturalendorphin

Endorphinreceptors

Properties of Water

Figure 3.3

Adhesion

Two types ofwater-conducting

cells

Cohesion

300 m

Directionof watermovement

Movement of Water Up Xylem Vessels

                                                                            

Cohesion – strong attraction of water molecules to each other

Adhesion – strong attraction of water molecules to walls of xylem

Figure 3.4

Figure 3.7

Cl Cl

Na

Na

Figure 3.8

+

+

Figure 3.6

Hydrogen bond

Ice:Hydrogen bonds

are stable

Liquid water:Hydrogen bonds

break and re-form

Figure 3.UN02

2 H2O Hydroxide

ion (OH)

Hydroniumion (H3O

+)

+

Figure 3.UN05

Acidic[H+] > [OH]

Neutral[H+] = [OH]

Basic[H+] < [OH]

Bases donate OH

or accept H+ inaqueous solutions

14

7

Acids donate H+ in aqueous solutions.

0