1.
Light is a form of energy. Light travels from the Sun to the Earth. _______________________ and ________________________________________ are other examples of light on Earth. Often sources of light give off heat.
Correct Answer
E. Fire and lightbulbs
Explanation
Light is a form of energy that can travel from the Sun to the Earth. Fire and lightbulbs are other examples of light on Earth. These sources of light not only emit light but also give off heat.
2.
Usually, a source of light gives off white light. White light is actually made up of ____________ colors. These colors range from red to violet.
Correct Answer
C. All
Explanation
White light is made up of all colors. When white light passes through a prism or is refracted, it separates into a spectrum of colors ranging from red to violet. This phenomenon is known as dispersion. Each color in the spectrum corresponds to a different wavelength of light, with red having the longest wavelength and violet having the shortest. Therefore, the correct answer is "all" as all colors are present in white light.
3.
All light is made of waves. A __________________________________ is the distance from the top of one wave to the top of the next wave.
Correct Answer
A. Wavelength
Explanation
A wavelength is the distance from the top of one wave to the top of the next wave. This is a characteristic property of waves and is used to measure the length of a wave. It represents the physical distance between corresponding points on adjacent waves, such as the distance between two crests or two troughs. By understanding the concept of wavelength, we can better comprehend the behavior and properties of light waves and other types of waves.
4.
A ________________________ is a range of light waves with different wavelengths and amounts of energy.
Correct Answer
D. Spectrum
Explanation
A spectrum is a range of light waves with different wavelengths and amounts of energy. It includes all the different colors of light that can be seen by the human eye.
5.
High-energy waves have ___________________ wavelengths and low-energy waves have _______________ ones.
Correct Answer
B. Shorter and longer
Explanation
High-energy waves have shorter wavelengths and low-energy waves have longer ones. This is because wavelength is inversely proportional to energy. High-energy waves carry more energy and therefore have shorter wavelengths, while low-energy waves carry less energy and have longer wavelengths.
6.
______________________ are places where light does not fall. They form when light is blocked. The light strikes an object but can't pass through it. It then has the shape of whatever is blocking the light.
Correct Answer
A. Shadows
Explanation
Shadows are places where light does not fall because they are formed when light is blocked. When light strikes an object but cannot pass through it, it creates a shadow that has the shape of whatever is blocking the light.
7.
Light travels in straight lines or ___________________. Shadows prove this. Light spreads out from a source in all directions, however it can't ____________________.
Correct Answer
E. Rays and bend
Explanation
Light travels in straight lines or rays and bend. Shadows prove this. Light spreads out from a source in all directions, however it can't bounce off and rays.
8.
Shadow size depends on where the light source is. The closer an object is to a light source, the ________________ the shadow.
Correct Answer
C. Bigger
Explanation
The closer an object is to a light source, the bigger the shadow. This is because when an object is close to a light source, it obstructs a larger portion of the light, resulting in a larger shadow being cast. The size of the shadow is directly proportional to the distance between the object and the light source, with closer objects casting bigger shadows.
9.
Most of the light that reaches your eyes is _____________________ light. Reflection occurs when light strikes a surface and __________________________ off.
Correct Answer
B. Reflected and bounces
Explanation
When light strikes a surface, it can either be absorbed, transmitted, or reflected. In this case, the correct answer is "reflected and bounces." This means that most of the light that reaches our eyes is reflected off surfaces and then bounces into our eyes, allowing us to see the objects around us.
10.
Light changes direction when it is reflected off a surface. The light source going towards a surface has oncoming rays. These rays strike the surface such as a mirror at an _________________________ angle. Outgoing rays are those reflected by the surface. They are reflected at an angle called an ____________________ angle.
Correct Answer
D. Incoming and outgoing
Explanation
When light is reflected off a surface, the incident rays that approach the surface are called incoming rays. These incoming rays strike the surface at an incoming angle. The rays that are reflected by the surface are called outgoing rays. They are reflected at an outgoing angle. Therefore, the correct answer is "incoming and outgoing".
11.
The Law of Reflection says that with reflection, the ______________________ angle is equal to the _____________________ angle.
Correct Answer
B. Oncoming and outgoing
Explanation
The Law of Reflection states that when light or any other wave reflects off a surface, the angle at which it approaches the surface (oncoming angle) is equal to the angle at which it leaves the surface (outgoing angle). This principle applies to all types of waves, including light waves.
12.
Refraction is the _________________ of light as it ____________________ from one material to another.
Correct Answer
E. Bending and passes
Explanation
Refraction is the bending of light as it passes from one material to another.
13.
Most materials ____________________ the light falling on them but some materials allow light to pass through them. Refraction happens when light passes through glass, water, light plastic, and other _________________________ objects.
Correct Answer
C. Reflect and transparent
Explanation
Some materials reflect the light falling on them, while others allow light to pass through them. Refraction occurs when light passes through transparent objects like glass, water, and light plastic.
14.
Light travels at different speeds in different materials. The thicker a material, the _______________ light travels through it. As light travels more slowly it bends more.
Correct Answer
A. Slower
Explanation
Light travels at different speeds in different materials, and the speed of light is inversely proportional to the density of the material. Therefore, the thicker a material is, the slower light travels through it. This is because the denser the material, the more particles there are for the light to interact with, causing it to slow down. As light travels more slowly through a thicker material, it bends more due to the change in speed between the two mediums.
15.
Lenses are tools that refract light. They are used to gather light rays or to spread them apart. There are two kinds of lenses: ________________________ and _______________________.
Correct Answer
D. Convex and concave
Explanation
Lenses are tools that refract light by bending it. They can be used to either gather light rays or to spread them apart. There are two main types of lenses: convex and concave. Convex lenses are thicker in the middle and thinner at the edges, causing light rays to converge. Concave lenses, on the other hand, are thinner in the middle and thicker at the edges, causing light rays to diverge. These two types of lenses have different properties and are used for different purposes in various optical devices.
16.
Convex lenses bulge in he middle. A convex lens brings rays of light together. A concave lens curves inward. A concave lens spreads light ray apart.
Correct Answer
A. True
Explanation
Convex lenses bulge in the middle and bring rays of light together, while concave lenses curve inward and spread light rays apart. Therefore, the statement "Convex lenses bring rays of light together" is true.
17.
When light reaches your eye it first passs through a thin, clear tissue overing each eye called the ________________________.
Correct Answer
B. Cornea
Explanation
The cornea is a thin, clear tissue that covers the front of the eye. It is the first structure that light encounters when it enters the eye. The cornea helps to focus light onto the retina, which is responsible for converting light into electrical signals that can be interpreted by the brain. The cornea also plays a role in protecting the eye from dust, debris, and other foreign objects.
18.
Then light passes through an opening called the _____________________. It's the black spot in the center of your eye.
Correct Answer
C. Pupil
Explanation
The pupil is the correct answer because it is the opening through which light enters the eye. It appears as a black spot in the center of the eye because it does not contain any light-sensitive cells. The cornea is the clear outer layer of the eye, the optic nerves transmit visual information to the brain, and the retina is the light-sensitive layer at the back of the eye.
19.
After light passes through your pupil, it travels through your lenses. Each lens focuses light on the back of your eye. A tissue called the __________________ covers the back of your eye.
Correct Answer
E. Retina
Explanation
After light passes through the lenses in your eye, it is focused on the back of your eye. The tissue called the retina covers the back of your eye and is responsible for detecting light and sending visual signals to the brain. The retina contains specialized cells called photoreceptors that convert light into electrical signals, which are then transmitted through the optic nerve to the brain for processing and interpretation.
20.
The images focused on your retina are actually upside down. Your retinas change the image into signals that travel along your _____________________________ to your brain. Your brain sees the picture rightside up.
Correct Answer
A. Optic nerves
Explanation
The images focused on your retina are actually upside down. Your retinas change the image into signals that travel along your optic nerves to your brain. Your brain sees the picture rightside up.
21.
__________________________ and ___________________________ are not true color. The either reflect all colors or absorb all colors causing them to be the color they are.
Correct Answer
E. White and black
Explanation
White and black are not true colors because they either reflect all colors or absorb all colors causing them to be the color they are. In the case of white, it reflects all colors of light, making it appear white. On the other hand, black absorbs all colors of light, resulting in the absence of color and the perception of black.
22.
Materials that block like wood, metal, and people are all opaque. Transparent materials let light pass through them like glass and water.Translucent materials reflect some light and let the rest pass through. Cloudy looking plastics are translucent.
Correct Answer
A. True
Explanation
The explanation for the given correct answer is that the statement is true. The passage clearly states that materials like wood, metal, and people are opaque, meaning they block light. It also states that transparent materials like glass and water let light pass through them, while translucent materials reflect some light and let the rest pass through. The passage also mentions that cloudy looking plastics are translucent. Therefore, based on the information provided, it can be concluded that the statement is true.
23.
Lasers are tubes of __________________. They use electricity to produce thin beams of light that have only 1 wavelength. All rays of a laser travel in the same direction making for a very intense, high-energy beam.
Correct Answer
B. Gas
Explanation
Lasers are tubes of gas. They use electricity to produce thin beams of light that have only 1 wavelength. All rays of a laser travel in the same direction making for a very intense, high-energy beam.
24.
Optical fibers are tubes made of glass or plastic. They keep the _______________________ energy inside the entire length of their fibers.
Correct Answer
C. Light
Explanation
Optical fibers are designed to keep the light energy inside their entire length. This is achieved through the principle of total internal reflection, where the light rays are continuously reflected off the inner walls of the fiber, preventing any significant loss of energy. As a result, optical fibers are widely used for transmitting information through light signals over long distances, as they can maintain the integrity and strength of the light energy throughout their fibers.