Notes: Introduction to Physical Science

INPUT

What is Physical Science?

Physical science is the study of matter, energy, and the changes they undergo.

-Matter is anything that has mass and takes up space.

-Energy is the ability to do work or cause change.

What are the branches of physical science?

1. Chemistry: properties of matter and how matter changes.

2. Physics: matter, energy, motion, forces, and how they interact.

What skills do scientists use to learn about the natural world?

Observation

Inference

Prediction

Observation

“The world is full of obvious things, which nobody by any chance ever observes”

-Sherlock Holmes

Today we will observe like scientists!

What is an observation?

Scientists use observation to make predictions.

What are the two types of observations?

1. Qualitative observation: qualities or characteristics of what is

being observed. Made by using any of the senses.

sight, smell, taste, touch, sound

What are the two types of observations?

2. Quantitative observation: The measurement of what is being observed. Made by using equipment.

rulers (cm or mm), balance (g), graduated cylinder (mL), beakers (mL), etc.

Discuss with your partner the qualitative and quantitative observations you can make about an apple. Record your results in the data table in your notes.

Qualitative Quantitative

Apple Observations

What is an inference?

Something we assume is true based on our observations. You make an inference when you explain your observations.

Based on reasoning from what you already know.

Inferences are not always correct! We can’t be sure it is true unless we test it in an experiment.

Discuss with your partner some inferences

you can make about this picture.

What is a prediction?

Making a forecast of what will happen based on past experience or evidence from observations.

Baloney Detection Kit

What makes a good experiment? The Baloney Detection Kit helps us to remember how to do an experiment correctly.

Baloney Detection Kit

1. Data should be ACCURATE. Use measurement tools properly. Ask if

you need help. Measurements should be precise.

In the string lab, we were accurate by measuring the mL of water at the bottom of the meniscus. We were precise by measuring to 100mL, not to 101 mL.

What is the difference between accuracy and precision?

ACCURACY How close a

measurement is to the true or actual value.

If it is 95 degrees outside and the thermometer reads 95 degrees, it is accurate. If it reads 92 degrees, it is inaccurate.

PRECISION Measure of exactness of

a measurement.

5.32 cm is more precise than 5.3 cm.

Baloney Detection Kit

2. Your experiment should be REPRODUCIBLE.

How close a group of measurements are to each other.

Repeat the experiment many times. You should get similar results. Only after repeating your experiment will you know if you have any errors.

In the string lab our results were reproducible because we did 4 trials. The more trials, the better.

Baloney Detection Kit

3. Experiments should only test only ONE VARIABLE at a time.

To be able to explain your data, you can only change one thing.

In the string lab how do you know what variable determined your results? Was it the angle, the tension, how fast you poured? It would have been better to change only one thing.

Baloney Detection Kit

4. Experiments should NOT have BIAS. No opinions allowed; only facts. Don’t be influenced by what you think will

happen. You must record and analyze your real results.

Never make up data!