An organized body of knowledge gathered over a long period of time to explain the world we live in.
Knowledge or a system covering general truths or the operation of general laws especially as obtained and tested through scientific method.
Scientific Method
1. Identifying the problem (Questioning) 2. Gathering Preliminary data 3. Formulating a hypothesis* 4. Testing of the hypothesis 5. Analysis and Interpretation of data 6. Drawing of Conclusion
Independent Variable – variable changed by the experimenter
Dependent Variable – variable that responds to the variable that is changed in the experiment.
Experimental group – groups that receive treatment.
Control group – opposite of Experimental.
hypothesis – it is what we think the answer to the question is and it should stated in terms of the variables defined.
Laws and Theories
*Scientific law – a description of a natural occurrence that has been observed many times.
*Scientific theory – a reasonable explanation of a scientific law. It is derived from a hypothesis that has been supported by repeated testing.
*Model – helps visualize occurrences and objects that cannot be observed directly.
Note: Scientific laws and theories cannot be proven absolutely. They are maintained as all observations support them.
Measurements
In science, the metric system is used in all measurements for its convenience and simplicity.
The International System of Units (SI) uses the seven base quantities and units given below:
Physical Quantity | Unit Name (symbol) | Mass | Kilogram, kg | Length | Meter, m | Time | Second, s | Amount of Substance | Mole, mol | Temperature | Kelvin, K | Electric current | Ampere, A | Luminous intensity | Candela, cd |
Reading Metric Measurements
No. of significant digits = no. of certain digits + one certain digit (0 or 5)
10 9
8 cm
Example 1: The diagram below is a metric ruler used to