1. 7th and 8th Grade Science Weiner High School
Science in our World
7th and 8th Grade Science
Weiner High School

2. What is Science?
Science is the knowledge obtained by observing natural events and conditions in order to discover facts and formulate laws or principles that can be verified or tested.

3. Scientific Methods…

4. Scientific Terms…
Hypothesis an explanation that is based on prior scientific research or observations and that can be tested.
Controlled experiment an experiment that tests only one factor at a time by using a comparison of a control group with an experimental group.
Variable a factor that changes in an experiment in order to test a hypothesis.

5. Models…
A model is a pattern, plan, representation, or description designed to show the structure or workings of an object, system, or concept.
We will discuss 3 types of models:
Physical Models
Mathematical Models
Conceptual Models

6. 3 Types of Models…
Physical Model : A model volcano and a miniature steam engine are examples of physical models. Some physical models, such as a model of a cell, look like the thing that they model. But a limitation of the model of a cell is that the model is not alive and doesn’t act exactly like a cell.

7. 3 Types of Models…
Mathematical Model: A mathematical model may be made up of numbers, equations, & other forms of data. Some mathematical models are simple & can be used easily. A Punnett square is an example of a mathematical model.

8. 3 Types of Models…
Conceptual Model: Some conceptual models are systems of ideas. Others compare unfamiliar ideas.
The idea that the solar system formed from a spinning disk of gas is a conceptual idea.
Scientist also use conceptual models to classify behaviors of animals for example.

9. Tools, Measurement, & Safety
A tool is anything that helps you do a task.
Tools for measuring: One way to collect data is to take measurements. To get the best measurements, you need the proper tools. Stopwatches, metersticks, balances, thermometers, spring scales, and graduated cylinders are all tools that scientists use to take measurements

10. Tools, Measurement, & Safety
Tools for analyzing: Perhaps you need to find the average of your data. Calculators are handy tools to help you do calculations quickly. Or you might show your data in a graph or a figure. A computer with the correct software can help you make neat, colorful figures. Of course, even a pencil and graph paper are tools that you can use to graph your data.

11. Tools, Measurement, & Safety
Units of measurement: Making reliable and accurate measurements is vitally important to science. In England at one time the standard for an inch was three grains of barley placed end to end. Other standards have been used in the past such as parts of the body. The foot was used for measurement but wasn’t really a reliable source for measurement, due to the differences in foot sizes.

12. International System of Units…
In the late 1700’s the French Academy of Sciences began to form a global measurement system known as the International System of Units, or SI. Today, most scientist and almost all countries use this system. The greatest advantage to using this system is that scientist around the world can compare their observations and results.

13. Measurement Terms… Meter The basic unit of length in the SI
Area A measure of the size of a surface or a region.
Mass A measure of the amount of matter in an object.
Volume A measure of the size of a body or region in three dimensional space.
Temperature The measure of how hot or cold something is.
Density The ratio of the mass of a substance to the volume of the substance.