CHM 121 Chapter 2: Chapter 2 Notes
7 Jun 2018
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2.1 Chemistry and The Elements
● Element: fundamental substance that can’t be chemically changed or broken down into
anything simpler
2.2 Elements and The Periodic Table
● Periods: 7 horizontal rows
● Groups: 18 vertical columns
● Main groups: two larger groups on the left and the six larger groups on the right
○ Most of the elements on which life is based- carbon, hydrogen, nitrogen, oxygen,
and phosphorus
● Transition metal groups: 10 smaller groups in the middle of the table
● Inner transition metal groups: 14 groups shown separately at the bottom of the table
2.3 Some Common Groups of Elements and Their Properties
● Property: any characteristic that can be used to describe or identify matter
○ EX: volume, amount, odor, color, and temperature
● Intensive properties: have values that do not depend on the amount of sample
○ EX: temperature and melting point
● Extensive properties: have values that do depend on the sample size
○ EX: length and volume
● Physical properties: characteristics that do not involve a change in a sample’s chemical
makeup
● Chemical properties: characteristics that do involve a change in a sample’s chemical
makeup
● Group 1A- Alkali metals
○ React rapidly, often violently, high reactivity, never found in nature in the pure
state but only in combination with other elements
find more resources at oneclass.com
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● Group 2A-Alkaline earth metals
○ Lustrous, silvery metals but are less reactive than their neighbors in group 1A
● Group 7A- Halogens
○ Colorful, corrosive non metals
○ Found in nature only in combination with other elements
● Group 8A- Noble gases
○ Colorless gases with very low chemical reactivity
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Element: fundamental substance that can"t be chemically changed or broken down into anything simpler. Main groups: two larger groups on the left and the six larger groups on the right. Most of the elements on which life is based- carbon, hydrogen, nitrogen, oxygen, and phosphorus. Transition metal groups: 10 smaller groups in the middle of the table. Inner transition metal groups: 14 groups shown separately at the bottom of the table. 2. 3 some common groups of elements and their properties. Property: any characteristic that can be used to describe or identify matter. Ex: volume, amount, odor, color, and temperature. Intensive properties: have values that do not depend on the amount of sample. Physical properties: characteristics that do not involve a change in a sample"s chemical makeup. Chemical properties: characteristics that do involve a change in a sample"s chemical makeup. React rapidly, often violently, high reactivity, never found in nature in the pure state but only in combination with other elements.
