There are many safety symbols that should alert you to the need for special safety precautions. The description of each symbol tells you which precautions to take whenever you work with something that has this symbol on it.
If you follow the instructions, you should have a safe and interesting year in the science laboratory.
Some symbols may differ slightly but the same precautions need to be taken.
Fire Hazard
When you see this symbol you will be working with fire.
· Never use any source of fire without safety goggles
· Never heat anything unless told to do so
· Never heat anything in a closed container
· Never reach across a flame
· Always use a clamp, tongs, or heat resistant gloves to handle hot objects
· Always maintain a clean work area.
Electrical Safety
Whenever you see this symbol, you know that your are using electricity
· Never use long extension cords
· Do not plug too many appliances into one
Socket
· Do not touch an electrical appliance with wet hands
Chemical Safety
Whenever you see this symbol, you know that you will be working with chemicals that could be hazardous.
● Never smell any chemical directly from its
container. Always use your hand to waft
some of the odors towards your nose.
· Never mix chemicals unless told to do so
· Never touch or taste any chemical unless
Instructed to do so.
· Keep all lids closed when chemicals are not in use.
Sharp Instrument safety
● Whenever you see this symbol, you know you
are working with a sharp instrument.
● Always use single sided razors.
● Handle any sharp instrument with care!
Always cut away from you, never towards you.
· Immediately notify your teacher if you get cut.
Glassware safety
● Whenever you see this symbol, you are working
with glassware that can be easily broken. Handle
such glassware carefully. Never use chipped or
cracked glassware.
● Never heat glassware that is not thoroughly dried.
● Never pick up hot glassware, use gloves.
● Always clean and dry glassware before putting it
away.
Heat Safety
• Whenever you see this symbol, you should put on
heat resistant gloves to avoid burning your hands.
Eye and Face safety
• Whenever you see this symbol, you will know that
you are performing an experiment win which you
must take precautions to protect your eyes and
face by wearing safety goggles.
• When you are heating a test tube or bottle
always point it away from you. Chemicals can
splash or boil out of a heated tube.
Animal Safety:
· Whenever you see this symbol, you will know that you are working with live animals.
· Do not cause pain, discomfort, or injury to an animal.
I. SCIENCE
A. What is Science??
Latin term meaning:
B. What do scientists do with this knowledge??
1. Make observations and inferences, then test using the
scientific method.
2. Carefully organize data using charts and graphs.
3. Solve problems.
II. BRANCHES OF SCIENCE
A. Biology
The study of ______.
EX: Marine biology, microbiology, cytology, ecology, genetics
B. Earth Science
The study of earth and its place in space.
EX: Geology, astronomy, meteorology, oceanography
C. Chemistry
This is the science dealing with the composition of matter.
EX: Organic chemistry, biochemistry, nuclear chemistry
D. Physics
This is the study of matter and energy and how it moves.
EX: Thermal energy, forces, waves, laws of motion
III. THE WORLD AROUND US
A. How do we, as young scientists, discover this
world?
1. OBSERVATION:
a) ______
b) ______
c) ______
d) ______
e) ______
2. GATHER, COLLECT AND ORGANIZE
Gather data through observation, and then organize it into charts and graphs to make it easier to interpret.
3. INFERENCE
A. An attempt to explain or interpret your observations
Observation: The grass on the school’s front lawn is wet.
Inference: It rained.
The sprinkler is on.
B. To conclude or deduct in a logical and reasonable
sequence
Observation: I noticed that a lima bean sprouted without
being in soil.
Conclusion: Lima beans don’t need soil to grow.
RULES FOR WORKING WITH A MICROSCOPE
1. ALWAYS carry microscope with one hand under base and other hand firmly wrapped around arm
2. Never clean objective lenses
with a paper towel.
3. Always begin with the scan
power objective.
4. When you are finished
with the microscope,
ALWAYS lower the stage and
leave the microscope with the
scan power objective in place.
5. Never turn the course adjustment when using the low and
high power objectives.
6. When determining the total magnification, one would multiply
the ocular (eyepiece) lens times the objective lens being used.
3 objective lenses (Eyepiece = 10x)
Scan power Medium power High power
4x 10x 40x
SWITCHING FROM LOW POWER TO HIGH POWER
You will notice 3 things when you go from low to high power:
1. Field of view will get smaller:
Scan Power High Power
2. Light Intensity decreases
3. Object gets closer
PARTS AND FUNCTIONS OF THE MICROSCOPE
PART / FUNCTION1.
Eyepiece
(ocular lens) / - lens closest to your eye
- magnification is usually 10x
2.
Body tube / - Connects eyepiece to the revolving
nosepiece
3.
Revolving Nosepiece / - holds and turns the objective lens into
viewing position
4.
Scan-power Objective / - always begin with scan power
- usually 4x
5.
High power Objective / - only to be used with fine adjustment
knob
- usually 40x
6.
Stage / - platform used to support the
microscope slide
7.
Stage clips / - holds the microscope slide in place
8.
Diaphragm / - regulates the amount of light entering
the body tube
9.
Course adjustment / - focuses the image under low power
- always use this as first step when
focusing in on your specimen
10.
Fine adjustment / - sharpens the image under low and high
power magnification
11.
Light source / - allows light to reflect upward through
the diaphragm, the specimen and the lenses
12.
Base / - provides support for the microscope
13.
Arm / - supports the body tube
TOTAL MAGNIFICATION:
Ocular lens (eyepiece) x Objective lens
EX: What is the total magnification using the eyepiece and high
power objective lens?
Formula: Ocular lens (eyepiece) x Objective lens
Substitution: 10x ● 40 x
Answer: 400x
TRY: What is the total magnification of an object using the eyepiece
and the low power objective lens?
Formula: Ocular lens (eyepiece) x Objective lens
Substitution:
Answer:
PART II
Describe the function of the parts of the microscope:
1. Body tube:
2. Revolving nosepiece
3. Stage
4. Diaphragm
5. Fine adjustment knob
6. Light source
7. Base
WET MOUNT SLIDE
STEPS USED TO PREPARE A WET MOUNT SLIDE:
1. Clean slide and cover slip THOROUGHLY
Glass slide Cover slip
2. Place specimen onto center of glass slide
3. Place 1-2 drops of water onto specimen. This will form a large
droplet with the specimen in the middle.
Side view of glass slide:
4. Slide cover slip at 45° angle until it touches water (use a teasing
needle). Drop cover slip down.
Teasing needle