Tools, Measurement, and Safety

1. Tools, Measurement, and Safety Section 4

2. Computers and Technology • The application of science for partical purposes is technology • Using technology, life scientists are able to find new information and solve problems in new ways • Get information that wasn’t previously available • The use of computers in science has helped scientists greatly • Create graphs and tables • Analyze data

3. Tools for Seeing • It is difficult to make accurate observations of things that cannot be seen • First microscope allowed scientists to see a whole new world • New tools and technology allow us to see inside organisms • CAT – computerized axial tomography • MRI – magnetic resonance imagery • electromagnetic waves travel through the body to create images

4. Compound Light Microscope • An instrument that magnifies small objects so that they could be easily seen • Common tool is life science laboratory • Consists of 3 parts • Tube with lenses • Stage • light • Items can be colored with special dyes to make more visible • Items placed on the stage so that the light passes through them

5. Electron Microscopes • Tiny particles called electrons are used to produce a magnified image • Images are clearer and have more detail • Living things can not be used because the preparation kills them • Two types of electron microscopes • Transmission electron microscopes (TEM) • Produces flat image • Scanning electron microscope (SEM) • Produces 3-D image

7. Measurement • The ability to make reliable measurements in an important skill in science • Different standards have developed throughout the world • Ancient times- people based measurements on parts of the body • Like the foot • Not reliable

8. The International System of Units • In the late 1700’s, the French Academy of Sciences began to form a global measurement system • Know as the International System of Units or SI Units or System International d’Unites • most scientists and almost all countries use this • Helps scientists share and compare results and observations

9. SI units are based on the number 10 • Easy for conversations • Centi = 100 • Milli = 1/1000 • Kilo = 1000

11. Length • Use cm, mm, or m depending on the size of the object • Also micrometers and nanometers are used for very small microscopic items • An ant= mm • A pencil = cm • Mackinac Bridge = km • Area • Measure of the size of a surrounding surface or region • Length x width • Units are always squared - m² cm² mm²

12. Volume • Is a measure of the size of something in three dimensional space • Volume of a liquid is often expressed in liters • Based on the meter • A cubic meter (m³) = 1000 L • 1mL = 1 cm³ • Use graduated cylinders to measure volume of a liquid

13. Volume of a solid is expressed in cubic units like cm³, m³ or mm³ • To find the volume of a regular shaped object multiply the length, width and height • L x w x h • To find the volumes of an irregular shape object, measure the volume of liquid the object displaces • Place liquid in graduated cylinder; measure • Add object and measure • The amount of liquid displaced is the volume of the object • Convert volume in liters to cubic meters • 1mL= 1 cm³

14. Mass • Is the measure of the amount of matter in an object • Kilogram is the basic unit for mass • Gram and milligram are also used • Metric ton is used for very large objects • Metric ton = 1000 kg • Mass is measured using a balance

15. Temperature • Measure of how hot or cold something is • Is an indication of the amount of energy within matter • Scientists commonly used Celsius, but Kelvin is the SI unit for temperature • We use Fahrenheit in the USA, but in class we will use Celsius • 212°F = 100°C • 98.6°F = 37°C • 32°F = 0°C

16. Safety Rules • Science is fun and exciting, but it can be dangerous too • Always follow instructions ( teacher’s and the book) • Don’t take shortcuts • Read lab procedures • Ask permission before experimenting on your own • Pay attention to the safety symbols • Know symbols • Page 27