Matter does “matter”!

What is matter? Matter is anything that has mass and takes up space. The “stuff” around us is made of matter, and we are made of matter also. Examples: air, plastic, metal, glass, paper, water, cloth, etc.!

Properties of matter Substance: a single kind of matter that is pure, meaning it was the same makeup, or composition, or specific set of properties. Every form of matter has two kinds of properties: Physical properties Chemical properties

Physical properties of matter A physical property is a characteristic of a pure substance that can be observed without changing it into another substance. A physical property of water is that it freezes at 0 C degrees (32 degree F) Other physical properties of matter are density, hardness, texture, shine, flexibility, and color.

Chemical properties of Matter A chemical property is a characteristic of a pure substance that describes its ability to change into a different substance. To observe the chemical properties of a substance, you must change it into another substance. Chemical properties are used to classify substances. An example would be a category of gases which are combustible vs. a category of gases which are not combustible

Elements Ancient Greeks believed that matter and all of the “stuff” in the world is comprised of four elements Earth, Fire, Water, and Air. An element is a pure substance that can not be broken down by chemical or physical means. Elements are the simplest of substances. The elements are found on the periodic table of elements.

Particles of Elements Atoms are the particles of elements An atom is the basic particle from which elements are made. Atoms are made of even smaller particles: A nucleus which is positively charged and it is surrounded by a cloud of electrons (which have a negative charge).

Atoms

Chemical bonds When atoms combine they form chemical bonds which is a force of attraction between two or more atoms. In many cases, atoms combine to form larger particles called molecules. Molecules are groups of two or more atoms held together by chemical bonds. Examples: water, oxygen, and carbon dioxide. Water Molecule (H 2 O) Oxygen Molecule (O 2 )

“Describing Matter” to be continued… Homework: “What is Matter” worksheet

Compounds Compounds are pure substances made of two or more elements chemically combined into a fixed ratio. A compound may be represented by a chemical abbreviation. When two or more elements are placed together the result is a compound which has different characteristics than either of the original elements. Calcium Carbonate (Compound) (Shell of a snail) Calcium (element) Carbon (element) Oxygen (element) CaCO 3

Mixtures Mixtures are substances held together by physical forces, not chemical. They can be separated physically. Solutions are also mixtures. Mixtures differ from compounds in two ways: 1) each substance in a mixture keeps its individual properties. 2) the parts of a mixture are not combined in a fixed ratio. Examples: oil and water, salt water, concrete

Heterogeneous Mixtures A heterogeneous mixture is when two or more substances are mixed but do not combine chemically to form a single substance. Examples: salad, oil and water, rocks, chocolate chip cookie, chicken soup, etc. We can separate all the components of the salad to the left, so it is a heterogeneous mixture.

Homogenous Mixture A homogeneous mixture is what you have when you mix two or more substances together so that the composition is the same throughout the mixture. Examples: sugar and water, brass (mixture of copper and zinc), air that we breathe (oxygen and nitrogen gases), soft drinks, milk, etc. A solution is an example of an homogeneous mixture.

The two types of changes in matter Physical changes: any change that alters the form or appearance of the matter, but does not alter the properties of the matter. A substance that undergoes a physical change is still the same substance after the change. Example: water exists as a solid, liquid, or a gas. Chemical changes: any change which results in the production of one or more new substances is a chemical change. The properties of the new substances are different than the properties of the original substances. Example: Hydrogen peroxide turns into water and oxygen gas when it is used.

Examples of Chemical Change Chemical change DescriptionExamples Combustioncombination of fuel and oxygen Gas, oil, coal ElectrolysisUse electricity to break down compounds. Breaking water into hydrogen and oxygen OxidationCombination of a substance with oxygen. Rust on a piece of iron TarnishCombining a bring metal with sulfur Tarnish on brass

Law of the conservation of matter Simply stated that when matter changes either chemically or physically, that matter is not created nor destroyed, it has just changed to another form or forms. Example: CH4 (methane) + 2O2 (oxygen) = CO2 (carbon dioxide) + 2H2O (water) Notice how the number of atoms did not change after the combustion.

Matter is neither created nor destroyed: Before the reaction CH 4 (methane) + 2O 2 (oxygen) The total number of atoms before the reaction is: 1 Carbon (C) 4 Hydrogen (H) 4 Oxygen (O) After the reaction CO 2 (carbon dioxide) + 2H 2 O (water) The total number of atoms after the reaction is: 1 Carbon (C) 4 Hydrogen (H) 4 Oxygen (O)

Homework: “Molecules and Compounds” worksheet