Lab safety, Lab equipment, & Experimental design Mrs. Green

Lab safety Report all accidents, injuries, and breakage of glass or equipment to the teacher immediately. Keep pathways clear by placing extra items (backpacks, books, ect) on the back of your chair, or under your chair, or away from the lab area. Long hair must be tied back to avoid catching fire (chin length or longer). Wear school appropriate clothing including closed toed shoes (no jackets). Work quietly, know what you are doing by reading the assigned experiment before you start. Pay close attention to all of the lab instructions.

Lab safety 6. Do not taste or smell chemicals (waft the smell). 7. Wear safety goggles to protect your eyes. 8. Unauthorized experiments or procedures are not permitted. 9. Leave your work station clean and in good order before leaving the lab. 10. Follow all instruction given by the teacher. 11. Make wise choices during the lab (no “horse play”). 12. No eating and drinking during the lab!

Lab equipment Triple beam balance Beakers There will be other types of lab equipment that we will use and I will explain each type as we come up to it.

Lab symbols

Experimental design Science – the process that uses observation and investigation to gain knowledge about events in nature Independent variable – is the variable that is changed by the experimenter on purpose in order to test its effects against the control group (x-axis) Dependent variable – the variable being measured in your experiment. The one that depends on the independent variable (y-axis) Control group – the part of the experiment that remains the same so that it may be used as a comparison to the independent variable. Usually the the “normal” outcome.

Experimental design Experiment – an organized procedure for testing the hypothesis Materials – supplies used to carry out the experiment Procedure – a numbered vertical list of the step-by- step directions for carrying out the experiments. Make sure these are clear and concise and another scientists can perform the same experiment. Reliability– the experiment must be repeated a minimum of 3 times to be reliable

Experimental design VS. Scientific Law – rule of nature that sums up related observations to describe a pattern in nature. Example: Law of Gravity Scientific Theory – an explanation based on experiments, the most logical explanation. Example: Black Hole Theory

Scientific Method Scientific Method – an organized set of investigation procedures used by scientists. 1. State the problem: (ask a question) the problem must be testable and written in the form of a question. For it to be testable it must have an identified control group and an experimental group. The key is to identify the 3 requirements involved in the experimental group. Independent variable, Dependent variable, Constant variable

Scientific Method 2. Research the problem Must be researched using appropriate reference material to support scientific understanding. You can use books, the internet, personal experiences, and others. 3. Form a Hypothesis This is an educated guess based on the research from the pervious steps. It’s valuable because it leads to further investigation, even if it turns out not to be supported by the data.

Scientific Method 4. Design Experiment 5. Gather & Analyze Data This step involves listing and gathering materials, developing and carrying out the procedures as well as identifying a control group and an experimental group. 5. Gather & Analyze Data Gather and figure out what the data means. The results of the experiment must be written based on the collected data

Scientific Method 6. Draw a Conclusion 7. Share the Results Write a summary that indicates whether or not the results support your original hypothesis. It is okay if your conclusion does not match your original hypothesis. 7. Share the Results Publish your scientific results and full experiment in a scientific journal for other scientists to repeat and replicate the results.

Scientific Method Quiz 1. Hypothesis a. standard for comparison 2. Control b. testable prediction 3. Dependent Variable  c. factor that is adjusted by the experimenter 4. Experiment  d. factor that doesn't vary in the experiment 5. Constant e. organized procedure for testing hypothesis 6. Independent variable  f. factor whose value is graphed on the y-axis

Scientific Research & Tools Observation – the process of gathering information about events or processes in an orderly way. Data – information gathered from observations. Inference – a logical interpretation based on prior knowledge, experiences and or collected data. Metric System – a decimal system of units based on a scale in multiples of ten (.10)

Scientific Research & Tools Microscopes – devices that produce magnified images of structures that are too small to be seen with the naked eye. 2 types of microscopes: Compound light microscope – allows light to pass through specimen and uses two lenses to form an image. Electron microscope – uses beams of electrons rather than light to form an image (1,000x more detailed then a light microscope)

Scientific Research & Tools Two main types of Scientific Research: Quantitative Research – research in which data is numerical in form. Example tools used: thermometer, balance, stopwatch Qualitative Research – research based on observation, the data is descriptive in form. Example tools used: binoculars, camera, tape recorder

Standards of Measurement International System of Units (SI) – standard system of measurement used worldwide. SI Base Units Quantity Measured Unit Symbol Length Meter m Mass Grams g Time Seconds s Electric current Ampere A Temperature Kelvin K Amu of Substance mole mol Intensity of light Candela cd

Standards of Measurement Length – distance between two points. Volume – the amount of space occupied by an object. Mass – the amount of matter in an object. Density – mass per unit volume of a material. Time – interval between two occurring events. Common SI Prefixes: Prefix Symbol Multiplying factor kilo k 1.000 deci d 0.1 centi c 0.01 milli m 0.001 micro 0.000001 nano n 0.000000001

Activity Time!

Activity Time!

Activity Time!

Graphing Graph – a visual display of information or data. Line graph – shows the trends or how the data changes over time. Bar graph – useful for comparing information collected by counting. Circle graph – (pie chart) used to show how a fixed quantity is broken down into parts.

The Science of Biology Biology – the study of life, also know as life science. Key aspect of Biology : the study of one living thing always involves studying other living things. Organism – things that have all the characteristics of life; made of one or more cells. Characteristics of Living Things: Organization (cells) Obtain / Use Energy Reproduce Respond to Stimuli Growth Homeostasis Development Adapt

The Science of Biology Life can be studied at the following levels: Human existence depends on the existence of all living things on Earth; wood, cotton, food, etc. Level: Description: Biosphere Part of Earth that contains all ecosystems Ecosystem Community and its nonliving environment Community Populations that live in defined areas Population A group of organisms of one type that live in the same area Organism Individual living Group of Cells Such as tissues, organs, and organ systems Cells The smallest functional unit of life Molecules Groups of atoms and smallest unit of a compound