1.
Electromagnetic waves have
Correct Answer
C. Both particle like and wavelike properties
Explanation
Electromagnetic waves exhibit both particle-like and wave-like properties. This is known as the wave-particle duality of electromagnetic radiation. On one hand, electromagnetic waves behave like particles called photons, which can transfer discrete amounts of energy. On the other hand, they also exhibit wave-like characteristics such as interference, diffraction, and polarization. This duality is a fundamental concept in quantum mechanics and is supported by numerous experimental observations.
2.
Emission of electrons when electromagnetic radiation falls on an object is
Correct Answer
A. Photoelectric effect
Explanation
The emission of electrons when electromagnetic radiation falls on an object is known as the photoelectric effect. This phenomenon occurs when photons of light transfer their energy to electrons in the object, causing them to be emitted. The photoelectric effect is an important concept in physics and has applications in various fields, such as solar panels and photocells.
3.
A _____ is a discrete,quantized bundle of energy.
Correct Answer
photon
Explanation
A photon is a discrete, quantized bundle of energy. Photons are elementary particles that are the fundamental units of light and other forms of electromagnetic radiation. They have no mass and travel at the speed of light. Photons exhibit both particle-like and wave-like properties, and their energy is directly proportional to their frequency. They are responsible for carrying electromagnetic energy and interacting with matter through processes such as absorption and emission.
4.
Name one use of the Photoelectric effect.
Correct Answer
solar panels
garage door sensors
nightlights
Explanation
The photoelectric effect is used in solar panels to convert sunlight into electricity. When photons from the sun strike the surface of the solar panel, they knock electrons loose from their atoms, creating an electric current. Garage door sensors also utilize the photoelectric effect. They use a beam of light to detect if an object or person is blocking the path of the door, triggering it to stop or reverse. Similarly, nightlights use the photoelectric effect to automatically turn on when it gets dark. They have a sensor that detects the absence of light and activates the light source.
5.
The Heisenberg Uncertainty Principal says that it is impossible to measure precisely both the position and momentum of a particle at the same time.
Correct Answer
A. True
Explanation
The Heisenberg Uncertainty Principle, a fundamental concept in quantum mechanics, states that it is impossible to simultaneously measure the exact position and momentum of a particle with complete accuracy. This principle arises from the wave-particle duality of quantum objects, where the act of measuring one property inherently disturbs the other. Therefore, the statement that it is impossible to measure precisely both the position and momentum of a particle at the same time is true.
6.
An atom in ____ is an atom with the smallest allowable amount of energy.
Correct Answer
C. A ground state
Explanation
An atom in a ground state is an atom with the smallest allowable amount of energy. In this state, the electrons occupy the lowest energy levels or orbitals around the nucleus. Excited states refer to when electrons have absorbed energy and moved to higher energy levels, while quantized energy refers to the discrete and specific energy levels that electrons can occupy. The air is not relevant to the concept of ground state energy levels in atoms.
7.
The ____ ____ is the region in which there is a high probability of finding an electron.
Correct Answer
electron cloud
Explanation
The electron cloud refers to the region around an atomic nucleus where electrons are most likely to be found. Electrons do not follow a fixed path, but rather exist in a cloud-like distribution of probabilities. This cloud represents the different energy levels and orbitals that electrons can occupy within an atom. The term "electron cloud" is used to emphasize the uncertainty and probabilistic nature of electron behavior in quantum mechanics.
8.
Light waves that are in step are know as incoherent light.
Correct Answer
B. False
Explanation
Incoherent light refers to light waves that are not in step or do not have a fixed phase relationship. Therefore, the given statement is incorrect. Light waves that are in step are known as coherent light.
9.
Laser stands for
Correct Answer
D. Light Amplification by Stimulated Emission of Radiation
Explanation
The correct answer is "Light Amplification by Stimulated Emission of Radiation". Laser stands for Light Amplification by Stimulated Emission of Radiation, which refers to the process of producing a highly concentrated beam of light through the stimulated emission of photons. This acronym accurately describes the fundamental principle behind laser technology, where the light is amplified and emitted in a controlled and coherent manner.
10.
Name one application of a laser.
Correct Answer
CD/DVD players
Laser pointers
Holograms
Cut steel and weld in factories
Reshape corneas in eyes
Replace knives in surgery for less blood loss
Explanation
Laser technology is widely used in various applications. CD/DVD players use lasers to read the data stored on discs. Laser pointers are commonly used for presentations and as a visual aid. Holograms are created using lasers to produce three-dimensional images. In factories, lasers are used to cut steel and weld materials with precision. In the field of medicine, lasers can reshape corneas in the eyes, providing an alternative to glasses or contact lenses. Additionally, lasers are used in surgeries as a substitute for traditional knives, resulting in less blood loss and faster healing.