Matter and Change Chemistry chapter 1

What does chemistry mean to me? Plastic Synthetic fabrics and materials Antibiotics and other drugs Chemical processes inside your body Chemistry chapter 1

What is a chemical? What isn’t a chemical? Chemistry chapter 1

What is chemistry? A physical science The study of the composition, structure, and properties of matter and the changes it undergoes. The science that seeks to understand what matter does by studying what atoms and molecules do. What are things made of? What are their internal structures? How do they react with each other? Chemistry chapter 1

What do chemists do? Relate properties of matter to structure of matter. Examine properties of existing materials to produce new materials. Chemistry chapter 1

Branches of chemistry Organic chemistry – most carbon-containing compounds Inorganic chemistry – compounds that don’t contain carbon (mostly) Physical chemistry – properties and changes in matter and energy Analytical chemistry – identification of components and compositions of mixtures Biochemistry – chemistry of living things Theoretical chemistry – using math and computers to understand chemical behavior and predict new compounds Chemistry chapter 1

Science and technology Basic research For the sake of learning Applied research Used to solve problems Technology Improves the quality of life Application of science for practical purposes Chemistry chapter 1

Discuss Read the “Modern Alchemy” section on pages 8 – 9. Discuss the following questions with someone seated near you. Are any discoveries in this feature accidental? Were the discoverers always aware of what they had discovered? Why don’t we use this “new alchemy” to make gold? Chemistry chapter 1

Matter Has mass and volume. Mass – measure of the amount of matter measured with a balance (scale) Volume – the amount of 3D space occupied Chemistry chapter 1

Parts of matter Element – a pure substance, only 1 kind of atom Atom – the smallest unit of an element that has the properties of that element Compound – made from the atoms of 2 or more elements that are chemically bonded Molecule – smallest unit of an element or compound that has the properties of that element or compound Contains more than one atom Chemistry chapter 1

Property A defining characteristic Can be used to classify into groups Chemistry chapter 1

Properties can be … Extensive – depend on the amount of matter present Length Mass Volume Amount of energy in a substance Intensive – do not depend on amount of matter Density Melting and boiling points Color flammability Chemistry chapter 1

Physical Properties Can be observed without changing the identity of the substance Melting and boiling points Color Density Mass Length volume Chemistry chapter 1

Physical changes Do not involve a change in the substance Grinding Cutting Melting Boiling folding Chemistry chapter 1

State changes Type of physical change Change from one state of matter (solid, liquid, gas, or plasma) to another Melting or freezing Boiling or condensing Chemistry chapter 1

Solids Have definite shape and definite volume Particles are close together Chemistry chapter 1

Liquids Have definite volume, but indefinite shape Take the shape of their container Particles are able to slip past each other Chemistry chapter 1

Gases Have indefinite shape and indefinite volume Expand to fill any container Particles can slip past each other and are usually far apart Chemistry chapter 1

Plasma High temperature physical state in which atoms lose their electrons Chemistry chapter 1

Chemical Properties Related to the ability to undergo change Can only be observed in a chemical reaction Ability to Rust Burn Rot Chemistry chapter 1

Chemical change When one or more substances are changed into different substances Also called chemical reaction Before the change the substances are called reactants After the change they are called products Chemistry chapter 1

Mixtures Contain two or more kinds of matter Not chemically combined Can be separated by physical means Homogeneous – the same throughout Heterogeneous – not the same throughout Homogeneous mixtures are also called solutions Chemistry chapter 1

Pure substances Elements or compounds Chemically combined Every sample has the same composition Chemistry chapter 1

Discuss Section review on page 18 Chemistry chapter 1

The Periodic Table Way to organize the elements Groups of elements– vertical columns Periods of elements – horizontal rows Chemistry chapter 1

Groups Numbered 1 to 18 Elements have similar chemical properties Have similar bonding abilities Also called families Chemistry chapter 1

Periods Physical and chemical properties change across a period Elements are more similar to others that are close to them Chemistry chapter 1

Lanthanides and Actinides Below the main body of the table Fit in after elements 57 and 89 Moved so that the table isn’t so wide What if they weren’t? Chemistry chapter 1

Metals Left and center parts of the table Mostly solids at room temperature Good conductors of heat and electricity Good tensile strength – can be pulled without breaking Malleable – can be pounded into sheets Ductile – can be drawn into fine wire Chemistry chapter 1

Nonmetals On the right side of the table Often gases at room temperature Solids are brittle Poor conductors of heat and electricity Chemistry chapter 1

Metalloids Next to the stairstep line on the table Have some properties of metals and some of nonmetals Usually semiconductors Chemistry chapter 1

Noble gases Group 18 Generally unreactive Only form compounds under specific lab conditions, not in nature Chemistry chapter 1

Discuss Section review on page 24 Chemistry chapter 1