Structure and Properties of Matter
Different kinds of matter exist and many of them can be either solid or liquid, depending on temperature. Matter can be described and classified by its observable properties.
Different properties are suited to different purposes.
A great variety of objects can be built up from a small set of pieces.
Chemical Reactions
Heating or cooling a substance may cause changes that can be observed. Sometimes these changes are reversible, and sometimes they are not.
Interdependent Relationships in Ecosystems
Animals depend on plants or other animals for food.
Plants depend on water, light and air to grow.
Some plants depend on animals for pollination and for dispersal of seeds from one location to another.
Biodiversity and Humans
There are many different kinds of living things in any area, and they exist in different places on land and in water.
Developing Possible Solutions
Designs can be conveyed through sketches, drawings, or physical models. These representations are useful in communicating ideas to other people.
The History of Planet Earth
Some events happen very quickly; others occur very slowly, over a time period much longer than one can observe.
Earth Materials and Systems
Wind and water can change the shape of the land.
Plate Tectonics and Large-Scale System Interactions
Maps show where things are located. One can map the shapes and kinds of land and water in any area.
The Roles of Water in Earth’s Surface Processes
Water is found in the ocean, rivers, lakes, and ponds. Water exists as solid ice and in liquid form.
Optimizing the Design Solution
Because there is always more than one possible solution to a problem, it is useful to compare and test designs.
Defining and Delimiting Engineering Problems
A situation that people want to change or create can be approached as a problem to be solved through engineering.
Asking questions, making observations, and gathering information are helpful in thinking about problems.
Before beginning to design a solution, it is important to clearly understand the problem.
Developing Possible Solutions
Designs can be conveyed through sketches, drawings, or physical models. These representations are useful in communicating ideas for a problem’s solutions to other people.
Optimizing the Design Solution
Because there is always more than one possible solution to a problem, it is useful to compare and test designs.