General organic and biological chemistry structures off life 5th CH4 elements and symbols GOB structures 5th ed

Lecture Presentation

Chapter 4
Elements and
Symbols

Karen C. Timberlake
General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake

© 2016 Pearson Education, Inc.


Chapter 4 Atoms and Elements
In addition to growing
crops and raising
animals, farmers must
understand how to
perform chemical tests
and how to apply
fertilizers and pesticides
or herbicides to crops.

General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake

© 2016 Pearson Education, Inc.


Chapter 4 Readiness
Key Math Skills

• Using Positive and Negative Numbers in Calculations (1.4B)
• Calculating Percentages (1.4C)
• Rounding Off (2.3)
Core Chemistry Skills
• Counting Significant Figures (2.2)
• Using Significant Figures in Calculations (2.3)

General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake

© 2016 Pearson Education, Inc.


4.1 Elements and Symbols
Elements
• are pure substances
from which all other
things are built.
• cannot be broken
down into simpler
substances.
• are listed on the inside
front cover of this text.
Learning Goal Given the name of an element, write its
correct symbol; from the symbol, write the correct name.
General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake

© 2016 Pearson Education, Inc.

Some Elements and Their Names
Element names come from planets, mythological figures,
minerals, colors, geographic locations, and famous people.

General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake

© 2016 Pearson Education, Inc.


Chemical Symbols
Chemical symbols
• represent the names of the
elements.
• consist of one to two letters
and start with a capital letter.
One-Letter Symbols Two-Letter Symbols
C carbon Co cobalt
N nitrogen Ca calcium
F fluorine Al aluminum
O oxygen
Mg magnesium
General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake

© 2016 Pearson Education, Inc.


Names and Symbols of Common Elements

General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake

© 2016 Pearson Education, Inc.


Chemical Symbols from Latin Names
Ag

silver (argentum)

Au

gold (aurum)

General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake

© 2016 Pearson Education, Inc.


Study Check
Write the correct chemical symbols for each of the following
elements:
A.
B.
C.
D.
E.

iodine
iron
magnesium
zinc
nitrogen

General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake

© 2016 Pearson Education, Inc.


Solution
Write the correct chemical symbols for each of the following
elements:
A.
B.
C.
D.
E.

iodine
=
iron
=
magnesium
zinc
=
nitrogen

I
Fe
= Mg
Zn
= N

General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake

© 2016 Pearson Education, Inc.


Study Check
Give the names of the elements with the following symbols:
A.
B.
C.
D.
E.

P
Al
Mn
H
K

General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake

© 2016 Pearson Education, Inc.


Solution
Give the names of the elements with the following symbols:
A.
B.
C.
D.
E.

P =
Al =
Mn=
H =
K =

phosphorus
aluminum
manganese
hydrogen
potassium

General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake

© 2016 Pearson Education, Inc.


Chemistry Link to Health: Toxicity of Mercury

Mercury (Hg)
• is a silvery, shiny element that is a liquid at room
temperature.
• can enter the body by mercury vapor inhalation, contact
with the skin, or ingestion of water or food contaminated
with mercury.
Once mercury has entered the body, it destroys proteins and
disrupts cell function. Long-term exposure can
• damage the brain and kidneys.
• cause mental retardation.
• decrease physical development.
General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake

© 2016 Pearson Education, Inc.


Chemistry Link to Health: Toxicity of Mercury
Mercury contamination comes from
• industrial wastes.
• fish and seafood.
• batteries.
• compact fluorescent bulbs.

General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake

© 2016 Pearson Education, Inc.

General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake

© 2016 Pearson Education, Inc.


4.2 The Periodic Table
The periodic table
organizes 118
elements into groups
with similar properties
and places them in
order of increasing
atomic mass.

Learning Goal Use the periodic table to identify the group
and the period of an element; identify the element as a
metal, a nonmetal, or a metalloid.
General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake

© 2016 Pearson Education, Inc.


Groups and Periods
In the periodic table,
• elements are arranged according to properties.
• groups contain elements with similar properties in
vertical columns.
• periods are horizontal rows of elements, counted

from top to bottom of the table as Periods 1−7.

General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake

© 2016 Pearson Education, Inc.


Periodic Table of Elements

General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake

© 2016 Pearson Education, Inc.


Group Numbers
Group numbers are written at the top of each vertical column.
• Use the letter A for representative elements
(Groups 1A–8A).
• Use the letter B for transition elements (Groups 3B–12B).
An alternative system uses numbers of 1–18 for all of the
groups, from left to right, across the periodic table.
Because both systems are currently in use, they are both
shown on the periodic table in this text and are included in our
discussions of elements and group numbers.

General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake

© 2016 Pearson Education, Inc.


Groups and Periods

Vertical columns represent groups of elements, and horizontal
rows represent periods.
General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake

© 2016 Pearson Education, Inc.


Group Names

General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake

© 2016 Pearson Education, Inc.


Alkali Metals
Group 1A (1), the alkali
metals, includes the
following:
• lithium (Li)
• sodium (Na)
• potassium (K)
• rubidium (Rb)
• cesium (Cs)

General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake

© 2016 Pearson Education, Inc.


Alkaline Earth Metals
Group 2A (2) elements, the alkaline
earth metals, are shiny but not as
reactive as Group 1A metals. They
include the following:
• beryllium (Be)
• magnesium (Mg)
• calcium (Ca)
• strontium (Sr)
• barium (Ba)
• radium (Ra)
Strontium gives the red color in fireworks.
General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake

© 2016 Pearson Education, Inc.


Halogens
Group 7A (17), the
halogens, includes the
following:
• fluorine (F)

• chlorine (Cl)
• bromine (Br)
• iodine (I)

General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake

© 2016 Pearson Education, Inc.


Study Check
Identify the element described by each of the following groups
and periods:
1. Group 7A (17), Period 4
A. Br
B. Cl

C. Mn

2. Group 2A (2), Period 3
A. beryllium
B. boron
3. Group 5A (15), Period 2
A. phosphorus
B. arsenic
General, Organic, and Biological Chemistry: Structures of Life, 5/e
Karen C. Timberlake

C. magnesium

C. nitrogen
© 2016 Pearson Education, Inc.