California science grade 5 (5)

In this section, you will see how scientists use inquiry skills, visual literacy, reading skills, technology and information literacy, math skills, and writing skills as they study volca

Investigate and Experiment

Lava flows from

an active volcano.

What Is

Science?

S cience is a way of understanding the world around us The work of scientists often begins when scientists ask questions about something they observe Asking and answering questions

is the basis of inquiry.

In this section, you will see how scientists use inquiry skills, visual literacy, reading skills, technology and information literacy, math skills, and writing skills as they study volcanoes.

Investigation and

Experimentation Inquiry Skills These are the inquiry

skills scientists use You can use these skills, too.

Observe Infer Classify Measure Use numbers Communicate Predict

Record Data Analyze Data Form a Hypothesis Use Variables Experiment Make a Model

7. Scientific progress is made by asking

meaningful questions and conducting

careful investigations As a basis

for understanding this concept and

addressing the content in the other

three strands, students should develop

their own questions and perform

investigations Students will:

a Develop a hypothesis.

b Select and use appropriate tools and

technology (including calculators,

computers, balances, spring scales,

microscopes, and binoculars) to

perform tests, collect data, and

display data.

c Construct appropriate graphs

from data and develop qualitative

statements about the relationships

between variables.

d Communicate the steps and results

from an investigation in written

reports and oral presentations.

e Recognize whether evidence

is consistent with a proposed

explanation.

f Read a topographic map and a

geologic map for evidence provided

on the maps and construct and

interpret a simple scale map.

g Interpret events by sequence and time

from natural phenomena (e.g., the

relative ages of rocks and intrusions).

h Identify changes in natural

phenomena over time without

manipulating the phenomena (e.g., a

tree limb, a grove of trees, a stream, a

hillslope)

3

T he diagram on this page shows what is usually called the “scientific method.” Scientists don’t always follow all these steps in the same order, but they often start with an observation about the world around us.

You, too, are constantly making observations every moment you are awake You might look out the window to see if it is raining You might listen for the sound of thunder to find out if a storm is coming.

Observation >

Inquiry Skills

When you make observations, you use these skills.

Observe Use your senses to learn about an object or event.

Classify Place things that share properties together in groups.

Measure Find the size, distance, time, volume, area, mass, weight, or temperature of an object

or an event.

Scientists are curious people who observe the world around

them and try to understand it To observe means to use your

senses to learn about something Scientists ask questions

about the things they observe You can too When you ask

questions about the things you see, smell, hear, taste, or feel,

you are a scientist

This photograph shows the town of St Pierre on the

island of Martinique It sits at the base of Mt Pelée, an active

volcano Why do you think scientists might want to closely

observe this volcano?

5

T he work of scientists often starts with an

unanswered question If scientists cannot find an

answer to a question, they go one step further

They propose a possible answer that can be

tested experimentally This is known as forming a

hypothesis A good hypothesis must

▸ be based on what you observe.

▸ be testable by performing an experiment.

▸ be useful in predicting new findings.

Scientists who study volcanoes are called

volcanologists This volcanologist is examining

lava as it flows into the ocean What do you think

happens to lava when it flows into ocean water?

Form a hypothesis to answer this question.

Question and Hypothesis >

Inquiry Skills

When you ask questions and form hypotheses, you use these skills.

Infer Form an idea from facts or observations.

Form a hypothesis

Make a statement that can be tested to answer

a question.

A scientific hypothesis must be testable That means

you must be able to support or disprove your hypothesis by

experimenting When you experiment you do a hands-on

activity to test an idea

Scientists often do research before they experiment

They look in books, scientific journals, or Internet resources

for information that other scientists have already learned

Scientists also know that they cannot rely on someone’s

opinion or claim unless it has been backed up by

observations

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S cientists test a hypothesis by doing experiments Although scientists don’t always wear lab coats or even work in a laboratory, every good experiment must

▸ change only one variable at a time.

▸ be able to be repeated.

Why are these two rules important? First,

scientists must be able to check each other’s work for accuracy Second, if you use more than one variable in an experiment, it may be difficult to identify the variable that was responsible for the results For example, scientists might measure

the temperature of lava at different locations on a volcano What would happen if they changed both the depth and the location at which they measured the temperature?

Inquiry Skills

When you experiment, you use these skills.

Experiment Perform

a test to support or disprove a hypothesis.

Use variables Identify things in an experiment that can be changed or controlled.

Predict State possible results of an event or experiment.

Make a model Make something to represent

an object or event.

Before you test a hypothesis, you must have a plan When

scientists make a plan, they think about the variables they

want to test A variable is something that can be changed

or controlled It is important to change or control only one

variable at a time Keep all other parts of the experiment the

same That way you will know that a single variable caused

your results

After they determine their variables, scientists decide

what materials they will need Then they write a procedure A

procedure is a series of numbered steps that tell what to do

and the order in which to do them

After scientists have developed their procedure, they

predict what will happen when they follow it To predict

means to tell what you think will happen

Experiment >

9

I n an experiment a scientist tries to observe

carefully and collect good data Once the data have been gathered, it is time to interpret it Collecting and interpreting data often requires working with numbers.

These volcanologists are taking samples of gases escaping from vents on the side of a volcano They are careful to wear protective clothing and gas

masks Why do you think it is important to know what gases are produced by a volcano?

Inquiry Skills

When you collect and interpret data, you use these skills.

Use numbers Order, count, add, subtract, multiply, and divide to explain data.

Measure Find the size, distance, time, volume, area, mass, weight, or temperature of an object

or an event.

Record data

Accurately arrange and store information collected in science investigations.

Analyze data Use the information that has been gathered to answer questions or solve a problem

When scientists follow their procedure, they make

observations and record data Data is information

Measurements are a type of data Scientists use

measurements whenever they can to describe objects and

events Scientists measure such things as length, volume,

mass, temperature, and time They use special tools, such

as rulers, thermometers, scales, balances, and binoculars to

make sure that their observations and measurements are

accurate

Scientists repeat their procedure several times This helps

them know if their results are correct They often compare

their results with other scientists Other scientists will repeat

the procedure to see if they get the same results

Collecting Data >

11

A fter interpreting the data, it is time to draw

a conclusion A conclusion is a statement about whether or not the hypothesis is valid based on the data collected Sometimes the data do not support the hypothesis Perhaps different experiments and observations are needed A new question may result.

Scientists also tell other scientists, as well as members of the public, about what they have

learned For example, the United States Geological Survey (USGS) operates five volcano observatories They observe activity leading to eruption, provide emergency information about future and ongoing eruptions, identify hazardous areas around active and potentially active volcanoes, and improve public understanding of how volcanoes erupt and change the enviorment.

Inquiry Skills

When you draw conclusions and communicate results, you use this skill.

Communicate Share information.

Scientists organize and analyze their data to see if the results

support or disprove their hypothesis They determine if their

prediction matched their results They draw conclusions and

try to explain their results When you draw conclusions you

interpret observations to answer questions

You communicate when you tell others what you have

learned Much of the communication done by scientists is

done by writing Scientists often write about their findings

and publish them in books and science magazines Scientists

do several things when they publish their findings They tell

other scientists what they are doing By making their findings

public, other scientists can also benefit when they work When

scientists communicate the results of their experiments, they

also make their results available for others to check As you can

see, scientists rarely, if ever, work alone

Sometimes the results of an experiment lead to new

questions These questions can be used to form a new

hypothesis and perform new experiements This way of working

is called the scientific method

Conclusion

13

Forming a Hypothesis

Lassen Peak, California

Pico de Orizaba, Mexico

Mount Fuji, Japan

Mount Erebus, Antarctica

Karymsky Volcano Kamchatka, Russia

Science often starts with unanswered questions,

and you can too In one class, a group of students

wondered if there was a pattern in the location of

volcanoes around the world This formed the basis for

their question

Question

Are volcanoes more common in certain places than in

others?

The students turned their question into a hypothesis

A hypothesis is a statement that can be tested to

answer a question A hypothesis can be formed as an

“If then ” statement

Hypothesis

If volcanoes most often occur in certain places, then

an analysis of volcano locations will show a pattern

Mount Shasta,

California

The World’s Volcanos Volcano Latitude Longitude

15

Testing a Hypothesis

The students decided to test their hypothesis by plotting on a map places where

volcanoes have erupted so that they could identify patterns

Procedure

1 On a small outline map, mark the locations where volcanoes are found Use the table of

volcano locations on page 15

2 Observe Are most volcanoes located near the edges or near the centers of continents?

6 IE 7.f Read a topographic map and a geologic map for evidence

Analyze Data

Does the map show a pattern in the arrangement of volcanoes?

Draw Conclusions

Are Earth’s volcanoes grouped in certain areas?

The students used this map to evaluate whether the results were

consistent with their hypothesis

Evaluating Evidence

6 IE 7.e Recognize whether evidence is consistent with a proposed explanation.

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Asking New Questions

Sometimes the result of an investigation can lead to new questions After analyzing the

data and communicating their results to the rest of the class, the students had another

question they wondered about

Question

Is there a relationship between the locations of active volcanoes and the location of

earthquakes?

Hypothesis

Write a hypothesis for this question What data do you need to answer this question?

Discuss the question with your classmates Work together to develop a plan to test your

hypothesis

6 IE 7.a Develop a hypothesis • 6 IE 7.d Communicate the steps and results from an investigation