SECTION I: DEFINING MATTER

 Chemistry is the study of the composition, structure and properties of matter, the processes that matter undergoes and the energy changes that accompany these processes.

 Matter is anything that has mass and volume.  Everything is made of matter

 Characteristics used to describe an object  Properties are used to identify a substance  Ex: color, odor, shape, size, texture, hardness

 Mass, weight, volume, and density

 Mass is the amount of matter in an object  Mass is constant and does not change with location.  Mass is also the measure of inertia  Inertia is the resistance of an object to changes in its motion  The more mass the greater the inertia

 1kg = 1000g  1 lb = 454g

 While mass deals with how much matter is present, weight takes into account the force of gravity.  Underwater and in space objects weight less than they do on earth but their mass is the same regardless of location.  Therefore, on Earth mass and weight represent the same thing.

 Volume is the amount of space that an object occupies.

 The volume of liquids are usually determined using a graduated cylinder.  Units of liquid volume: milliliter, liter, gallon, pint, etc.  1L = 1000mL

 Volume of a regularly shaped solid is determined using a geometric formula BOX: Volume = length X width X height CYLINDER: Volume = ∏r 2 h Units of solid volume: cm 3 1mL = 1cm 3

 Volume of a dry powder can be measured using a graduated measuring cup.

 Volume of an irregularly shaped object can be determined by immersing the object in water and measuring the amount of water displaced.

 Extensive Properties-a characteristic that is specific to the amount of matter.  In other words, the property changes with the amount of the substance.  Ex. Mass, volume, weight, & length are extensive properties.  Extensive properties alone are not sufficient in identifying a substance.

 Density- the amount of substance or mass contained in a certain space.  The mass per unit volume.  Density is useful in identifying the composition of a substance.  Temperature alters the density of a substance

 Density = mass/volume  Common Units of Density = g/mL, g/cm 3

 The density of water at room temperature is 1.0g/mL.  Any object with a density greater than 1.0g/mL will sink in water.  Any object with a density less than 1.0g/mL will float in water.

MaterialDensityMaterialDensity Zinc7.1g/cm 3 Gold19.3g/cm 3 Paper0.8g/cm 3 Brass8.4g/cm 3 Water1.0g/mLCopper9.0g/cm 3 Aluminum2.7g/cm 3 Lead11.4g/cm 3

 Intensive Properties-a characteristic that does not depend on the size or amount of matter.  In other words, the property remains constant regardless of the amount of the substance.  Ex. Density, color, hardness, boiling point, melting point, etc.  Intensive properties are useful in identifying a substance.