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)