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Physical Science. Physical science is the study of matter and energy. Matter: has mass and takes up space book, tree, light, etc. Energy: the ability of a system to do work. Work: transfer of energy through motion Heat, sound
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Physical Science • Physical science is the study of matter and energy. • Matter: has mass and takes up space • book, tree, light, etc. • Energy: the ability of a system to do work. • Work: transfer of energy through motion • Heat, sound • Everything, living & nonliving can be categorized as either matter or energy.
Matter can be identified by its properties (characteristics). • Some properties are shared by lots of different matter, some are unique.
Nickel(Ni) Aluminum (Al) Silver (Ag) Type: metal metalmetal Color: silver color silver color silver color Location: Earth’s crust Earth’s crust Earth’s crust State: solid solidsolid Melting Point: 6600C 9620C 14550C Boiling Point: 24670C 22120C 27320C Density: 2.7 g/cm3 10.5 g/cm3 8.9 g/cm3
If you have samples of unknown matter, you can use the unique characteristic properties to identify them. • Melting Point: the temperature at which a solid melts into a liquid. • Boiling Point: the temperature at which a liquid turns into a gas (“vaporizes”) • Density: mass per unit volume; how tightly packed the matter is.
Al Ni Ag V= 1 cm x 1cm x 1cm V=1 cm3 V=1 cm3 V = 1 cm3 m= 2.7g m=10.5g m=8.9g Density = mass volume DAl= 2.7 gDAg= 10.5 gDNi= 8.9 g 1cm3 1cm31cm3 DAl= 2.7g/cm3DAg= 10.5g/cm3DNi= 8.9g/cm3 If 2 objects have the same volume, then the heavier one is denser. D =
Measuring Volume • Regular shaped objects have volume defined by geometric equations. • Rectangular prism: V= l x w x h • Sphere: V= (4/3)∏r3 • Cylinder V= ∏r2h • The volume of an irregularly shaped object can be measured through water displacement.
Archimedes discovered this technique while trying to discover if a crown was made of pure gold for his employer King Heiron II.
Relative Density • The density of pure water is 1 g/mL. • 1g/mL = 1 g/cm3 • Objects that have a greater density than water will sink in water, those with lesser density will float.
Density Problem 1 An empty shoebox has the dimensions 20cm x 40cm x 10 cm. Its mass is 200 g. What is its density? D=m/v V=l x w x h V=(20cm x 40cm x 10 cm) V= 8000 cm3 D=(200g/8000cm3) D=0.025 g/cm3
Density Problem 2 • The shoebox is now full of sand and has a mass of 10,000 g. What is its density? D=m/V D=(10,000g)/8000cm3 D= 1.25 g/cm3
Density Problem 3 A chunk of metal with a mass of 4.5 g is dropped into a graduated cylinder with 13.5 mL of water in it. If the water level rose to 15.3 mL after the metal was added, what is the density of the metal? D=m/V V= Vafter – Vbefore V= 15.3mL-13.5mL V=1.8 mL D=4.5g/1.8mL D=2.5 g/mL
Density Problem 4 If the density of silver is 10.5 g/cm3, what would be the mass of a 2200cm3 block of it? D=m V 10.5 g = m 1 cm3 2200 cm3 (1 cm3) (m) = (10.5 g)(2200 cm3) m = (10.5g)(2200 cm3) (1 cm3) m = 23100 g
Density Problem 5 If you have 500 g of shampoo that has a density of 2g/mL, what is its volume? D=m/V 2 g = 500 g 1 mL V (1mL) (500g) = (2g) V (1mL) (500g) = V 2g 250 mL = V
Types of Properties Physical Property: one that can be observed without changing the identity of the substance. • Color, shape, size, texture, melting/boiling pt. magnetism,