Chemistry Properties of Matter Section 2.1

Properties of Matter Bamboo has properties that make it a good choice for use in chopsticks. It has no noticeable odor or taste. It is hard, yet easy to split, and it is heat resistant. Which of these properties is physical? Which is chemical? 2.1

Properties of Matter There are 2 types of properties you’ll be studying this year: intensive and extensive 2.1

Properties of Matter Extensive Properties  An extensive property is a property that depends on the amount of matter in a sample The mass of an object is a measure of the amount of matter the object contains. The volume of an object is a measure of the space occupied by the object. 2.1

Properties of Matter Intensive Properties  An intensive property is a property that depends on the type of matter in a sample, not the amount of matter. The hardness or density of a bowling ball is an example of an intensive property. Flammability, reactivity, and color are other intensive properties 2.1

Identifying Substances Matter that has a uniform and definite composition is called a substance.  Substances may be elements or compounds  The substance seen below is an element: Cu. (Copper) 2.1

Intensive vs. Extensive Properties  Will all samples of the same substance have the same extensive properties? No. Extensive properties depend on the AMOUNT of matter, not what the matter is composed of.  Will all samples of the same substance have the same intensive properties? Yes. Intensive properties depend on what the matter is composed of. 2.1

Using Properties to Identify Substances  A physical property is a quality or condition of a substance that can be observed or measured without changing the substance’s composition. In other words, observing the property doesn’t change the identity of the substance.  Water is still Water. Paper is still Paper, etc.  Hardness (or density), color, conductivity, and malleability are examples of physical properties. 2.1

Examples of Physical Properties 2.1

States of Matter Three states of matter are solid, liquid, and gas. 2.1

States of Matter Solids  A solid is a form of matter that has a definite shape and volume.  Particles move in place- vibrate  Attractions are strong enough that particles can’t move past each other  Particles are close together 2.1

States of Matter Liquid  A liquid is a form of matter that has an indefinite shape, flows, yet has a fixed volume.  Attractions are strong enough to keep particles close but weak enough to let particles move past each other 2.1

States of Matter Gases  A gas is a form of matter that takes both the shape and volume of its container.  Particles have very little attraction for each other and move very quickly, so they can move past each other easily  Particles are far apart 2.1

States of Matter file:///C:/Chemistry%20Presentatio nExpress/Chapter02/Section01/Che mASAP/dswmedia/rsc/asap1_chem 05_cman0201.html file:///C:/Chemistry%20Presentatio nExpress/Chapter02/Section01/Che mASAP/dswmedia/rsc/asap1_chem 05_cman0201.html

States of Matter  Vapor describes the gaseous state of a substance that is generally a liquid or solid at room temperature Like water vapor 2.1

Physical Changes  During a physical change, some properties of a material change, but the composition of the material does not change.  In the picture, you can see Gallium melting- it was gallium when it was solid and still is gallium as a liquid 2.1

Physical Changes  Physical changes can be classified as reversible or irreversible. All physical changes that involve a change from one state to another are reversible. Cutting hair, filing nails, and cracking an egg are examples of irreversible physical changes. 2.1