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Chemistry. Chapter 1 -2. What is Matter . Matter: Anything that has mass and volume Ex: Air we breathe When we blow up a balloon it has more mass and a greater volume than when it was deflated. What is Matter?. Volume: Space that an object occupies Ex: Textbook – It takes up space
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Chemistry Chapter 1 -2
What is Matter • Matter: • Anything that has mass and volume • Ex: • Air we breathe • When we blow up a balloon it has more mass and a greater volume than when it was deflated
What is Matter? • Volume: • Space that an object occupies • Ex: • Textbook – It takes up space • How do we measure the volume of a liquid? • Must be read the same way EVERY time!
What is Matter? • Mass: • Quantity of matter in an object • How do we measure mass? • Electronic balance • Triple beam balance’ • Mass is related but not identical to weight
What is Matter? • Weight: • Force produced by gravity acing on mass • The weight of an object depends on where it is. Whereas the mass of an object will always be the same no matter where it is in the universe. • Ex: An astronaut weighs about 6 times more on Earth than on the moon because the effect of gravity is less on the moon. His mass though remains constant!
Units of Measurement • In class we will use quantitative terms – numbers – to make descriptions more accurate. • Ex. 15 grams of sugar instead of a spoonful • Quantity: • Has magnitude or size • Unit: • Standard used when measuring a quanity
Units of Measurement • Ex. You can measure the quantity mass with the unit kilogram. • What quantity is measured with the unit meters?
Units of Measurement • In 1960 the standard system of measurement units was adopted • There are 7 base units which you can find in Table 1-3 on page 12
Units of Measurement • We will be converting from 1 unit to another • Conversion Factor: • Mathematical expression that relates two units • Ex: Convert 1.5 kg to grams
Units of Measurement • Derived units: • Created from combinations of the base SI units • Volume • Multiple length, width, and the height of an object • m x m x m = m^3 • Make sure when converting to do it 3 times to end up in m^3
Units of Measurement • 1000 cm^3 • 0.001 m^3 • 1000000 mm^3 • All of these equal 1 L
Properties of Matter • Relationships between properties can be represented by graphing • When you look at the graph on page 15 what do you notice? • The mass of the aluminum is directly proportional to its volume
Properties of Matter • The slope of the line equals the ratio of mass • Slope = y2 – y1/ x2 – x1 • Density: • Ratio of mass to volume • Density = mass / volume
Density • Unit for density is g/cm^3 • Look at Figure 1-11 • Which substances have a density of less than 1 and how do you know? • We can also use density to figure out mass or volume • D X V = m • m / D = V
Density • If you found a bracelet on the street and you wanted to find out if it was made of real silver what would be your first step? • Mass = 199.0 g • Volume = 20.5 cm^3 • D = m / V • 199.0 g / 20.5 cm^3 = 9.71 g/cm^3 • Look at Table 1-5 to find the density of silver and determine if the bracelet is actually made of silver
Physical Properties • Physical Property: • Any property of matter that can be measured without changing its chemical nature. • Ex: Mass, volume, and density • Ex: Color, texture, melting point, and boiling point
Physical Properties • Physical Changes: • Change that affects only the physical properties • Ex: Melt water to get ice you still have H2O • Ex: Boil water to get steam
Physical Changes • Physical changes can involve changes in energy • Melting & Boiling are endothermic changes because heat is transferred to the substance from the surroundings • Freezing & Condensation are exothermic changes because heat is transferred from the substance to its surroundings.
Chemical Properties • Chemical Property: • Property of matter that can be observed only when substances interact with one another. • Chemical Change: • A change that produces one or more new substances.
Chemical Properties • Evidence a chemical change has occurred. • The evolution of a gas- we can see gas bubbling or the emission of an odor. • Formation of a precipitate – insoluble solid • Evolution or absorption of heat – increase or decrease in temperature
Chemical Properties 4. The emission of light – light is produced 5. Color change – look at Figure 1-13 letter d. This shows the color change of an indicator in the presence of a base.