Introduction to Matter Section 1.1 Describing Matter

1. Matter: is anything that has mass and takes up space. Ex: all the stuff around you is matter. You are matter too . Ex: air, plastic, wood, glass, and cloth

I. Properties of Matter A. Matter can have many different properties, or characteristics. Ex: hard, soft, rough, smooth, hot, cold, solid, gas B. Chemistry: is the study of the properties of matter and how matter changes. a. substance: is a single kind of matter that is pure (always has a specific makeup or composition and a specific set of properties) Ex: Salt water

C. Every form of matter has two kinds of properties 1. physical property 2. Chemical property D. Physical Property: is a characteristic of a pure substance that can be observed without changing it into another substance Ex: water = freezes at 0 degrees Celsius (even though the water is frozen, it is still water) Can be used to classify matter Ex: metals = classified by luster and the ability to conduct electricity, malleability, ductile, etc…

Chemical Property: is a characteristic of a pure substance that describes its ability to change into different substances. 1. also used to classify substances Ex: Methane gas (natural gas) = very combustible…creates new substances when it combines with oxygen as it burns. Ex: Burning, flammability, or oxidation More examples: iron + oxygen = rust, silver + sulfur = tarnish, for all my bakers out there…yeast + dough ingredients = CO2 (bread rises)

II. Elements! A. Element: is a pure substance that cannot be broken down into any other substances by chemical or physical means. 1. Elements are the simplest substances. a. Each element can be identified by its specific physical and chemical properties Ex: Al=aluminum (foil and outdoor furniture) ZN= zinc (used in pennies) O= oxygen (breath it in)

B. Particles of Elements – Atoms 1. atom- is the basic particle from which all elements are made. a. different elements have different properties bc their atoms are different B. Has a positive charged nucleus, and a negative charged cloud around the nucleus C. When atoms Combine 1. Chemical bond – is a force of attraction between two atoms. a. Molecules – are groups of two or more atoms held together by chemical bonds. Ex. Molecule of water = oxygen atom chemically bonded with two hydrogen atoms

Ex: Diatomic Molecules = two atoms of the same element bonded III. Compounds A. Compound – is a pure substance made of two or more elements chemically combined in a set ratio. Chemical Formula - represents a compound and shows the elements in the compound and the ratio of atoms. EX: CO2 = carbon dioxide (the number 2 represents that there are 2 oxygen atoms for every one atom of carbon.) EX: CO = carbon monoxide

B. When elements are chemically combined, they form compounds having properties that are different form those of the uncombined elements. Ex: Silver (shiny metal) + Sulfur (yellow powder) = Ag2S(black compound called tarnish) Ex: Sugar = C12H22O11 IV. Mixtures A. mixture = is made of two or more substances – elements, compounds, or both – that are held together in the same place but are not chemically combined Each substance in a mixture keeps its individual properties. Also, the parts of a mixture are not combined in a set ratio.

B. 2 types of Mixtures: 1. Heterogeneous mixture- you can see different parts of this mixture Ex: salad 2. Homogenous Mixture – the substances are so evenly mixed that you can’t see the different parts. Ex: Sugar water (can not see the sugar but you know it is there bc you can taste it)

a. Solution – an example of a homogenous mixture. Ex: can be a liquid, solid, or gas Ex: air = nitrogen gas, oxygen, and small amounts of other gases Ex: brass = solution of copper and zinc. Separating Mixtures: a. Compounds can be very difficult to separate b. Mixtures are much easier to separate 1. techniques to separate a mixture: Ex: using a magnet Ex: Filtering the mixture Ex: Distilling a Liquid Solution Ex: Evaporation

Total Cereal Demonstration