What is Matter?

CHEMISTRY- the scientific study of the composition, structure, and properties of matter and the changes that matter undergoes MATTER- anything that has mass and take up space Ex of matter: (class will give examples and write them down) Light and sound are matter? Why?

ELEMENT- a substance that cannot be separated or broken down into simpler substances by chemical means Each element is made of only one kind of ATOM ATOM- smallest unit of an element that maintains the properties of that element Symbols for elements are always a single capital letter or a capital letter followed by a lowercase letter (ex: carbon- C, iron- Fe, copper- Cu, aluminum- Al)

Earth and the human body differ in the kind and proportion of elements are composed of COMPOUND- a substance made of atoms of two or more different elements that are chemically combined (give one example)

A water molecule can be represented by a formula, physical models, or computer images Every compound is different from the elements it contains (ex: the elements hydrogen oxygen, and nitrogen are colorless gases, but when combine with carbon to form nylon, the strands of nylon are flexible solid)

MOLECULE- the smallest unit of a substance that keeps all of the physical and chemical proprieties of that substance (the smallest unit of a substance that behaves like a substance) A water molecule is made of two hydrogen and one oxygen atom Most molecules are made of atoms of different elements, but also be made of atoms of the same element:

CHEMICAL FORMULA- a combination of a chemical symbols and numbers to represent a substance Ex: Indigo is the dye first used to turn jeans blue, the chemical formula of indigo is shown in fig., and it is made of 4 elements and 30 atoms In a chemical formula, the number of atoms of each element is written after the element’s symbol

Numbers placed in front of a chemical formula show the number of molecules Three molecules of table sugar are written as: 3C12H22O11, each molecule of sugar contains 12 carbon atoms, 22 hydrogen atoms and 11 oxygen atoms Ex: How many elements and atoms have : acetic acid C2H4O2, glucose C6H12O6, table salt (sodium chloride) NaCl, water H2O

PURE SUBSTANCE- a sample of matter, either a single compound that has definite chemical and physical proprieties Pure= not mixed with anything Pure substance is matter that has a fixed composition and definite proprieties Ex:- water is a pure substance made up of elements hydrogen and oxygen, which are chemically combined - grape juice, the components, such sugar and water are not chemically combined

Grape juice is a MIXTURE A MIXTURE- a combination of two or more substances that are not chemically combined A mixture may have proprieties that are similar to the pure substance that form it (Ex: grape juice: liquid (water), sweet (sugar) Some mixtures are made by putting solids and liquids together

Lab: determine differences between given mixtures Draw a table: Substance 1 Substance 2 Observations Combine, sugar with water, flour with water, sand with water, and syrup with water Write in the table observations, and write down the conclusions

HOMOGENEOUS ( homo- the same)- the substance are evenly distributed (a sample from the bottom of a glass should have the same composition as a sample from the top) HETEROGENEOUS (hetero: different)- the substances aren’t mixed uniformly, and are not evenly distributed From the lab examples, which examples are homogeneous, and which are heterogeneous, write down the reason