Science Chapter 1 Review
Km to m
0.42 km: 420 m
What are the rules for recognizing significant figures?
1. All non-zero digits are significant 2. All zeros between non-zero digits are significant 3. All beginning zeros are not significant (Ending zeros are significant if the decimal point is actually written in but not significant if the decimal point is an understood decimal.) Helps you round to the significant value, and only for decimal.
What are the three types of graphs we will use this year?
1. Line graph 2. Bar graph 3. Circle graph
What are the three main branches of science?
1.) Physical science 2.) Earth science 3.) Life science.
If the density of water is 1.0 g/ml and I calculate the density of water to be 1.2 g/ml, what is my percent error?
1.2-1.0/1.0*100 -> (0.2/1)*100 -> 0.2*100 -> 20%
If I find the length of the room to be 15.6 m, the height to be 3.6 m, and the width to be 8.9 m, what is the volume? How would I round this answer following the significant figures rules?
15.6*3.6*8.9= 499. 824--50
Kg to g Mg to g
50 kg: 50,000 g 4630 mg: 4.63 g
Variable
A factor that can change in an experiment
Scientific notation
A method of writing or displaying numbers in terms of a decimal number between 1 and 10 multiplied by a power of 10. The numbers are either super small or super large.
Significant Figure
A prescribed decimal place that determines the amount of rounding off to be done based on the precision of the measurement
Scientific Method
A series of steps followed to solve problems including collecting data, formulating a hypothesis, testing the hypothesis, and stating conclusions.
Scientific Law
A statement that universally holds for a certain class of phenomena
System
A system is a set of parts that work together to achieve a particular, more complex goal.
Hypothesis
A testable prediction, often implied by a theory
What is a hypothesis referred to as after being verified by a large number of independent experiments?
A theory
Constant
A value that does not change
Independent variable
A variable (often denoted by x ) whose variation does not depend on that of another, and is changed
Scientific Theory
A well-tested explanation for a wide range of observations or experimental results. They are also continually tested, forever.
Science
An organized way of gathering and analyzing evidence about the natural world, through experiments and observation.
Experiment
Are test under controlled conditions designed to demonstrate something scientists already know or to test something scientist wish to know
Qualitative data
Descriptive data, using words
Scientific Fact
Direct and repeatable observation of any aspect of the natural world. An agreement between trained investigations
Scientific Notation
Example: 15,400 mm: 1.54*10^4 mm 2050 ml: 2.05*10^3 ml .0015 kg: 1.5*10^-3 kg 800,000,000 m: 8*10^8 m If the exponent is positive move the decimal point to the right; If the exponent is negative move the decimal point to the left
How many significant figures are in each of the following numbers?
Example: a. 1200-2 b. 1201-4 c. 12.01-4 d. 0.0012-4 e. 12.100-5 f. 12-2
Control
In an experiment, the standard that is used for comparison
Observation
Information obtained through the senses.
Devried units
Is a SI unit of measurement comprised of a combination of the seven base units
Line graph
Is a type of chart used to show information that changes over time. We plot line graphs using several points connected by straight lines.
Bar graph
Is used to show how something changes over time or to compare items. They have an x-axis (horizontal) and a y-axis (vertical). Typically, the x-axis has numbers for the time period or what is being measured, and the y-axis has numbers for the amount of stuff being measured.
Circle graph
Is used to visualize information and data. A circle graph is usually used to easily show the results of an investigation in a proportional manner. The arcs of a circle graph are proportional to how many percent of the population gave a certain answer.
SI prefixes
Kilo: 1,000 Hecto: 100 Deka: 10 Deci: 0.1 Centi: 0.01 Milli: 0.001
What are the steps of the scientific method?
Make an observation. Ask a question. Form a hypothesis or testable explanation. Make a prediction based on the hypothesis. Test the prediction. Review results: use the results to make new hypotheses if wrong or if right test the hypothesis again.
Dependent variable
The measurable effect, outcome, or response in which the research is interested.
Percent error
The ratio of an error to an actual value, the observed value of the error divided by the accepted value, multiplied by 100%
Facts about Theories
Theories forever and are constantly being retested with every experiment and observation. Theories can never become a fact or law.
Hypotheses and theories are
explanations
Accuracy
how close a measurement is to the true value, not exact
Quantitative data
numerical data, using numbers
Laws and measurements are
observational
Precision
the exactness of a measurement
experiment group
the group exposed to manipulation of independent variable,
International System of Units/Metric System
the system of units (SI) used by scientists to measure the properties of matter L: Meter (M) M: Kilogram (Kg) T: Celsius (C) T: Second (S)