Tools, Meas, Safety Ch1.4 7th
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Transcript of Tools, Meas, Safety Ch1.4 7th
CHAPTER 1 SECTION 4
Tools, Measurement, and Safety
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?