CHAPTER 1 I. DESCRIBING MATTER

HINT: Vocabulary words are this color! Put them into your vocabulary section of you spiral as we go.

A. MATTER - anything that has mass & volume. 1. Properties (characteristics) of matter - used to identify substances * ex.s - flammability, color, shape, texture, temperature 2. CHEMISTRY - the study of the properties of matter & how matter changes

B. KINDS OF MATTER 1. ELEMENTS -substances that cannot be broken down into any other substance by chemical or physical means. - building blocks of matter - all matter is composed of elements - made up of ATOMS - each element has its own symbol - can exist in combined or uncombined form

Copper - Cu is copper’s symbol

Mercury - Hg

Gold - Au

Sulfur - S

Uranium - U

2. COMPOUNDS - substances made of 2 or more elements chemically combined in a specific ratio & having their own specific properties. * ex.s - CO2 carbon dioxide - H2O water - H2O2 hydrogen peroxide

a. FORMULA - H2O - this is a formula. *The formula: - uses symbols to identify which elements are present. - shows the ratio of elements in a compound.

3. MIXTURES - 2 or more substances that are mixed but NOT chemically combined. Most matter found in the environment occurs in mixtures! Mixtures differ from compounds in 2 ways: 1. Substances keep individual properties ex. - soil, salt water 2. Parts of mixtures do not come in specific ratios

C. CHANGES IN MATTER 1. Physical change - a change that alters the form or appearance of a material but does not make the material into a new substance. Ex.s - chopping wood, bending wire, painting a car, ice melting to water

What is the difference between these two statues? Is this physical or chemical ?

2. CHEMICAL CHANGE A change in matter that produces new substances. Substance contains the same elements but atoms are rearranged in new combinations. Ex.s - rusting, burning, oxidation

Burning trees are chemically changed into other substances like carbon and ash.

II. MEASURING MATTER - Sect. 2 A. MASS - the amount of matter in an object. Units of Mass - grams (or kilograms)

ARE MASS AND WEIGHT THE SAME?? NO!! REMEMBER - mass is the amount of matter in an object. Weight is the affect of gravity on an object’s mass!

B. Volume - the amount of space an object takes up. Volume = length x width x height Units of volume - liter - cubic centimeter

C. Length - distance Units of length - meters

D. Density - how much mass is contained in a given volume. To calculate the density of an object, divide its mass by its volume. D = M/V Units of density - g/cm3

Everything’s density is compared to water. Water’s density is 1.0 g/cm3 So if an object has a density of 3.5 g/cm3, does it sink or float? How about an object with a density of 0.47 g/cm3?

III. PARTICLES OF MATTER A. ATOMS - the smallest possible piece of an element with all the properties of that element. 1. 1st thought of by Democritus (440 b.c.e.) an ancient Greek a. atomos - “uncuttable”

2. Dalton - (1802) British teacher formed ideas through experiments DALTON’S IDEAS: formed the basis of our modern understanding of atoms 1. Atoms can’t be broken into smaller pieces. 2. Atoms of different elements are different.

4. Atoms of each element have a unique mass. 3. Atoms of 2 or more elements can combine to form compounds. 4. Atoms of each element have a unique mass. 5. The masses of the elements in a compound are always in a constant ratio.

B. Atoms today 1. Atoms are very small number of atoms in 1 grain of sand = (more than all the grains of sand on the whole beach!!) There are 2,000 billion oxygen atoms in 1 drop of water 2,000,000,000,000,000,000,000 & 4,000 billion hydrogen atoms !!!

Imagine a marble in the center of this stadium - It would be the atom’s nucleus (99.9% of an atom’s mass) the rest the electron cloud.

C. Atoms & Molecules 1. Chemical bonds - the force that holds atoms together to form molecules. MOLECULE - the combination of 2 or more atoms that are bonded together. Ex.’s - H2O = 1 molecule of water O2 = 1 molecule of the oxygen we breathe C2H4O2 = 1 molecule of a simple sugar

Some molecules can be huge. They may contain millions of atoms.

The DNA molecule

IV. Elements From Earth A. (Integrating Earth Sci.) 1. Gold (Au) 19.3 g/cm3 a. Pyrite (Fool’s Gold) 5.0 g/cm3 HOW WOULD THIS BE USEFUL TO KNOW? b. Gold’s density allows it to be “panned”

2. Compounds in Nature a. Most elements are found in compounds ex.s - copper compounds, iron ores 1. Ores are rocks that contain metal or other economically useful materials. 2. To separate elements from the compounds they are found in, requires a chemical reaction.

Electrolysis - “electric cutting” A chemical reaction & a way of breaking apart a compound. - copper Heat may also be used to chemically break apart compounds. - iron forges (blast furnaces)