Results

Patterns and processes of evolution. How evolution and natural selection are reflected in the similarities and differences of organisms. 

Video 1: Construction of a circle when its radius is known
Video 2: Examples of how to construct a circle
Video 3: Common mistakes made when constructing a circle

Video 1: How to construct a line segment
Video 2: Examples of constructing different line segments
Video 3: Common mistakes made when constructing a line segment

Video 1: What are perpendiculars and perpendicular bisectors and how to construct them
Video 2: How to draw a perpendicular and perpendicular bisector using a ruler and a compass
Video 3: Examples related to the construction of perpendiculars and perpendicular bisectors on a line segment
Video 4: Common mistakes made when constructing perpendiculars and perpendicular bisectors

There are many different processes and phenomena that emit electromagnetic radiation. Humans have taken advantage of many of these processes to develop technologies that use electromagnetic radiation.

Video 1: How to construct a copy of an angle
Video 2:
Video 3: Common mistakes made when constructing an angle as a copy of another

Video 1: How to construct angles of a given measurement using paper and a protractor 
Video 2: How to construct angles of a given measurement using a compass
Video 3: Examples of constructing angles of specific measurements
Video 4: Common mistakes made when constructing angles of specific measurements

The beauty of a coral reef, the warm radiance of sunshine, the sting of sunburn, the X-ray revealing a broken bone, even microwave popcorn—all are brought to us by electromagnetic waves. The list of the various types of electromagnetic waves, ranging from radio transmission waves to nuclear gamma-ray (γ-ray) emissions, is interesting in itself.

Even more intriguing is that all of these different phenomena are manifestations of the same thing—electromagnetic waves (see Figure 15.1). What are electromagnetic waves? How are they created, and how do they travel? How can we understand their widely varying properties? What is the relationship between electric and magnetic effects? These and other questions will be explored.

An image that illustrates light reflecting off a plain mirror.

Food webs are models that demonstrate how matter and energy is transferred between producers, consumers, and decomposers as the three groups interact within an ecosystem. Transfers of matter into and out of the physical environment occur at every level. Decomposers recycle nutrients from dead plant or animal matter back to the soil in terrestrial environments or to the water in aquatic environments. The atoms that make up the organisms in an ecosystem are cycled repeatedly between the living and nonliving parts of the ecosystem.