Intro. to Chemistry

What is Chemistry? The study of the composition and changes of matter.

What is Matter? – All living and nonliving things – Anything with mass – Anything that takes up space What isn’t Matter? – Energy (light, waves, etc)

Areas of Study Organic Chemistry – – The study of all chemicals containing carbon. – Ex. Living things

Areas of Study Inorganic Chemistry – The study of chemicals that do NOT contain carbon. – Ex. Studying rocks (non-living)

Areas of Study Biochemistry – The study of the chemical processes that take place in organisms – Ex. Muscle contraction and digestion.

Areas of Study Analytical Chemistry – The area of study that focuses on the composition of matter. – Ex. Amount of lead in drinking water.

Areas of Study Physical Chemistry – The study that deals with the mechanism, the rate, and the energy of chemical changes.

How do we describe matter? Matter has extensive properties. Extensive properties are properties that depend on the amount of matter in a sample. – Examples: Mass Volume Length

Matter has intensive properties. Intensive properties are properties that depend on the type of matter in a sample, NOT the amount. – Examples: Hardness Shape Luster Malleability Ductility Conductivity Melting/Freezing Point Color Odor

Matter has physical properties. Physical properties identify the substance without changing it. – Examples: Physical State (solid, liquid, gas) Color Melting Point Boiling Point

Matter has chemical properties. Chemical properties identify the substance as it chemically reacts. – Examples during a reaction: Rusting Burning Odor given off Temperature change

Matter can go through physical changes. – Change where type of substance does not change. – Reversible changes (sometimes irreversible) – Examples: Changes of state Changes of shape Changes of texture Breaking

Matter can go through chemical changes. – Changes where material becomes a new substance – Involves a chemical reaction – NOT usually reversible – Always involve reactants and products – Include processes such as: burning, exploding, rusting, corroding, fermenting, rotting – Evidence of chemical changes: Energy transfer Gas production Precipitate Change of color

Chemical Reactions Conserve Mass Law of conservation of mass - in chemical reactions mass is not created nor destroyed Mass of reactants = Mass of products CH 4 + 2O 2  CO 2 + 2H 2 O

Classifying Matter Matter can be classified as either a mixture or a pure substance.

Mixtures Heterogenous mixture: not uniform – Example: soup, salad dressing

Homogenous mixture: uniform – Homogenous mixtures are also known as solutions. – Examples: air, steel, nickel – Solution Examples: Salt water Beer Pop

Mixtures are only physical combined. We can separate them by the following: – Filtration-separate by size or state – Distillation-separated by boiling point

Classifying Matter Elements: – Metals – Nonmetals – Metalloids

Classifying Matter Compounds and Molecules: – Substance that contains 2 or more elements chemically combined in a fixed ratio.

Memorize common elements. Memorize the 7 diatomic molecules.