Physical Science Notes—Chapter 1

Science is a method for ___________________.

• It is a process that uses ____________________________ to gain ______________________ about events in nature.

Nature follows a ____________________________.

Many rules, such as those concerning how the human body works, ______________________.

• Other rules, such as the fact that Earth rotates about once every 24 h, _________________________.

• Scientists ask questions to _________________________________________.

Science can be classified according to _______________________________.

• Life science deals with _______________________.

• Earth science investigates ____________________.

• Physical science deals with _________________________________.

• Sometimes, a scientific study will ______________________________________.

• One scientist, for example, might study the motions of the human body to understand how to build better artificial limbs.

Scientific explanations help you ______________________________________.

• As more is learned about the natural world, some of the earlier explanations might be found to be _____________________________ or new technology might provide _______________________.

Scientists learn new information about the natural world by _________________________________, which can be done in many different ways.

• Some investigations involve simply _________________________________ and recording the observations.

• Other investigations involve _____________________________ that test the effect of one thing on another.

• Some investigations involve building a model that resembles something in the natural world and then ________________________________________________________.

An organized set of investigation procedures is ____________________________________.

• _____________________________ found in scientific methods are shown.

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• Many scientific investigations begin when someone ________________________________________ and wonders ___________________________ it occurs.

• Then the question of ______________________________ is the problem.

Before testing a hypothesis, it is useful to learn as much as possible about the _____________ ________________________________.

A hypothesis is a _________________________________ using what you know and what you observe.

• Some hypotheses can be tested by ___________________________.

• Others can be tested by ___________________________ and relating it to _____________________________________________.

• One common way to test a hypothesis is to _________________________________.

• An experiment tests the effect of one thing on another _______________________________.

• A variable is a quantity that can have __________________________________.

• You might set up an experiment to determine which of three fertilizers helps plants to grow the biggest.

• Possible factors include plant type, amount of sunlight, amount of water, room temperature, type of soil, and type of fertilizer.

• In this experiment, the amount of growth is the ___________________________________ because its value _________________________________ the changes in the other variables.

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• The variable you change to see ________________________________________________ is called the independent variable.

• A factor that __________________________ when other variables change is called a constant.

• You might set up four trials, using the same soil and type of plant.

• Each plant is given the same amount of sunlight and water and is kept at the same temperature. These are ________________________.

• The fourth plant ____________________________.

• This plant is a ________________. A control is the ___________________________________ can be compared.

• Suppose that after several days, the three fertilized plants grow between 2 and 3 cm.

• If the unfertilized plant grows 1.5 cm, you might infer that the growth of the fertilized plants was _________________________________.

• Analyzing the Data

• An important part of every experiment includes ______________________________ and _________________________________________ into easy-to-read tables and graphs.

• _________________________ the data and _____________________________ the observations is an important step.

• If the data are not organized in a logical manner, ____________________________ can be drawn.

• Drawing Conclusions

• Based on the analysis of your data, you decide whether or not your hypothesis is ________________________________.

• For the hypothesis to be considered valid and widely accepted, the experiment must result in __________________________________________________ it is repeated.

• A bias occurs when what the scientist expects __________________________________ are viewed.

• This expectation might cause a scientist to select a result from one trial over those from other trials.

• Scientists can lessen bias by running __________________________________ and by keeping _______________________________ of each observation made.

• Valid experiments also must have data that are measurable.

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• For example, a scientist performing a global warming study must base his or her data on ____________________________ of global temperature.

• The experiment must be ______________________________.

• Findings are supportable when other scientists perform the ______________________ _________________________________

• Visualizing with Models

• Sometimes, scientists cannot _______________________ that they are testing.

• They might be observing something that is _____________________________ _________________ to see completely.

• A model represents an _______________________________ to help people better understand it.

• Today, many scientists use ________________________ to build models.

• NASA experiments involving space flight would not be practical _____________________.

• Another type of model is a ____________________________.

• Scientific Theories and Laws

• A scientific theory is an explanation of things or events based on ________________________ _______________________________. It is not a guess.

• Just because a scientific theory has data supporting it does not mean ______________________________________________.

• A scientific law is a statement about what happens in nature and that _____________________________________________________.

• Laws tell you what will happen under certain conditions, but they ____________________ ______________________ something happens.

• ___________________ is an example of a scientific law.

• A theory can be used to _____________________________________.

• Even so, there are few theories in science and even fewer laws.

• Science can help you explain many things about the world, but science ____________________ ______________________________.

• Most questions about emotions and values are not ____________________________.

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• They _____________________ be tested.

• Technology is the _________________________________ to help people.

• For example, when a chemist develops a new, lightweight material that can withstand great amounts of heat, ________________________________.

• When that material is used on the space shuttle, _________________________________.

Section 2: Units and Standards

• A standard is an exact quantity that people _______________________________ measurements.

• For a measurement to make sense, it must include a ______________________________.

• The ______________________________ of measurement is commonly used in the United States

• Most other nations use the ______________________________¾a system of measurement based on multiples of ten.

International System of Units

• All SI standards are __________________________________ by scientists throughout the world.

• Each type of SI measurement has a ____________________________.

• The _______________ is the base unit of ________________.

Every type of quantity measured in SI has a _________________________________________.

• All other SI units are obtained ____________________________________.

SI Prefixes

• The SI system is easy to use because it is based on _______________________________.

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• Prefixes are used with the names of the units to ______________________________________ should be used with the units.

Converting Between SI Units

• A conversion factor is a ______________________________ and is used to change one unit to another.

• To convert units, you multiply by the _______________________________________.

• Use the conversion factor with new units (mL) in the numerator and the old units (L) in the denominator.

Measuring Distance

• In scientific measurement length is the _____________________________.

• The SI base unit of length is the ________________________.

• ___________________ and ________________________ are used to measure length.

• The size of the unit you measure with will depend on _____________________________ being measured.

Measuring Volume

• The __________________________________ is called its volume.

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• If you want to know the volume of a solid rectangle, such as a brick, you measure its __________________________________________ and _____________________ the three numbers and their units together (V = 1 x w x h).

• For a brick, your measurements probably would be in __________________________.

• The volume would then be expressed in ______________________________.

Measuring Liquid Volume

• In measuring a liquid’s volume, you are indicating the _______________________________ that holds that amount of liquid.

• The most common units for expressing liquid volumes are ______________________________.

• Sometimes, liquid volumes such as doses of medicine are expressed in _____________________.

Measuring Matter

• Mass is a measurement of the _____________________________ in an object.

Density

• The _________________________________ of an object can be used to find the density of the material the object is made of.

• You find density by dividing an object’s __________________________________________.

Derived Units

• The measurement unit for density, g/cm3 is __________________________________ of SI units.

• A unit obtained by combining different SI units is called a _____________________________.

• An ______________________________________ also is a derived unit.

Measuring Time and Temperature

• Time is the _____________________________ two events.

• The SI unit for time is the _______________________________.

• For most scientific work, temperature is measured on the _________________________________.

• On this scale, the _______________________ of water is 0°C, and the _______________________ of water is 100°C.

• Between these points, the scale is divided into __________________________ divisions. Each one represents 1°C.

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• The SI unit of temperature is the ________________________.

• Zero on the Kelvin scale (0 K) is the __________________________________, also known as absolute zero.

• Absolute zero is equal to _______________________________________the freezing point of water.

• Kelvin temperature can be found by adding ___________________________________. So, on the Kelvin scale, water freezes at 273 K and boils at 373 K.

• The temperature measurement you are probably most familiar with is the ________________________________, which was based roughly on the temperature of the human body, 98.6°.

Section 1.3: A visual Display

• A graph is a _____________________________________________________.

• This is a graph that shows a girl walking her dog.

• The horizontal axis, ______________________, measures time.

• Time is the __________________________ because ______________________________, it affects the measure of another variable.

• The __________________________ that the girl and the dog walk is the other variable.

• It is the __________________________ and is measured on the vertical axis, or _______________.

Different kinds of graphs¾line, bar, and circle¾are appropriate for displaying different types of information.

• A line graph can show any relationship where the dependent _______________________________________ in the independent variable.

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• Line graphs often show how a relationship between variables ______________________________.

• You can show _______________________________________________ as long as the relationship between the variables is identical.

• The most important factor in making a line graph is always using _______________________ ____________________________________.

• The y-axis always is used for the _________________________________.

Bar Graphs

• A bar graph is useful for comparing information _________________________________. For example, suppose you counted the number of students in every classroom in your school on a particular day and organized your data in a table.

• You could show these data in a _____________________ like the one shown.

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• As on a line graph, the _______________________________________ is plotted on the x-axis and the ________________________________ is plotted on the y-axis.

Circle Graphs

• A circle graph, or pie graph, is used to show how down _________________________________.

• The circular pie represents the __________________.

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• The slices represent _________________________ and usually are represented as ________________________________ of the total.

• To create a circle graph, you start with the total of what you are analyzing.

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