Tools, Meas, Safety Ch1.4 7th

Tools, Measurement, and Safety CHAPTER 1 SECTION 4

Objectives Provide 3 examples for how scientists use computers

and technology Describe 3 tools that scientists use to observe

organisms Explain the importance of the International System

of Units (provide 4 examples)

Computers Technology: application of science for practical

purposes 1st electronic computer was built in 1946 Computers can create graphs, solve complex

equations, analyze data Help scientists share ideas, publish reports

Tools for Seeing Compound Light Microscopes  

Magnifies small objects to be seen easily 3 main parts: tube with lenses, stage, light

Transmission Electron Microscope (TEM)  

Use electrons to produce magnified images Electrons pass through the specimen to produce a flat image

Scanning Electron Microscope (SEM) 

Electrons bounce off of the surface of the specimen to produce a 3-D image

Measurement International System of Units (SI Units) Developed in the late 1700’s All units based on the number 10 Conversions are easier

Length SI Unit is the meter Conversions:      

Kilometer (km): 1km = 1,000m Decimeter (dm): 1 dm = 0.1m Centimeter (cm): 1cm = 0.01m Millimeter (mm): 1mm = 0.001m Micrometer (μm): 1µm = 0.000001m Nanometer (nm): 1nm = 0.000000001m

Area A measure of the size of a surface or region Calculated using units of length and width Stated in square units (m²), (cm²), (km²)

Volume The measure of the size of something in 3-D space Most often described in liters (L) Liters are based on the meter One cubic meter: 1m³ = 1,000L One cubic centimeter: 1cm³ = 1mL

Mass The measure of the amount of matter in an object Basic SI unit of mass is the kilogram (kg) Very large objects are measured in

metric tons = 1,000kg

Temperature How hot or cold something is The amount of energy within matter Commonly measured in:  

Fahrenheit (ºF) Celsius (ºC)

SI unit of temperature is the Kelvin (K) – notice no

degree symbol!

Temperature comparisons

212 ºF and 100ºC – water boils 32ºF and 0ºC – water freezes 98.6ºF and 37ºC – normal body temperature Kelvin???

Quick Quiz

What is the SI unit for length, mass, and

temperature? What is the area of a compact disc case with sides

measuring 14cm and 12.5cm?