Unit 1 Chapter 1 Notes Scientific Measurement What

Unit 1 – Chapter 1 Notes – Scientific Measurement

• What are SI Units? – A standard system of measurement – SI = International System of Measurement • Why use SI Units? – So that all scientists can speak the same language – Compare and analyze data the same way all around the world

• The Metric System is based on 10: – Each unit is 10 times larger or 10 times smaller than its neighbor

• The major prefixes: – Kilo = 1000 times larger – Centi = 100 times smaller – Milli = 1000 times smaller

Many Kids Have Dropped Over Dead Converting Metrics Many Nights Mega kilo hecto deca/ deka ONE deci centi milli micro nano

• Distance is measured with METERS – Meters = m – Kilometers = km • 1 km = 1000 m – Centimeters = cm • 1 m = 100 cm – Millimeters = mm • 1 m = 1000 mm

• What is mass? – The amount of MATTER (stuff) in an object – This is a constant NEVER CHANGES!!! • MASS & WEIGHT ARE NOT THE SAME!!!

• Measured in GRAMS – Gram = g – Kilogram = kg • 1 kg = 1000 g – Centigram = cg • 1 g = 100 cg – Milligram = mg • 1 g = 1000 mg

• What is weight? – The measure of attraction of 2 objects due to gravity – This CAN CHANGE it is not a constant • Think of person in outer space they weight less but still have the same amount of matter • Gravity depends upon: – Distance between 2 objects – Size of objects

• Measured with seconds – Second = s – Kilosecond = ks – Centisecond = cs – Millisecond = ms

• What is volume? – The amount of space an object takes up • Solids measure with cm 3 • Liquids measure with LITERS – 1 m. L = 1 cm 3

• Measured in DEGREE CELSIUS in a lab – Water freezes at 0 – Water boils at 100 • SI Temperature = KELVIN – There is no “ 0” on the Kelvin scale – To obtain Kelvin = C + 273