Laser Light and Atomic Reactions

The video tutorial explores the properties of ultraviolet light and its effects on objects like spiders and UV-painted test tubes. It demonstrates fluorescence and explains the formula E=hf, which relates photon energy to frequency. The tutorial includes experiments with different colored laser lights and calculations of photon energy and wavelength, emphasizing the use of Planck's constant and the wave equation.

What type of light is used in the experiment to make the spiders react?

• Visible light

• Ultraviolet light

• Infrared light

• X-ray light

Which formula is introduced to explain the energy of photons?

• E = mc^2

• E = hf

• F = ma

• V = IR

What happens when the red laser light is shone on the spiders?

• Nothing happens

• The spiders change color

• The spiders move rapidly

• The spiders glow brightly

Which color of laser light causes a reaction similar to the ultraviolet torch?

• Red

• Green

• Purple

• Yellow

What constant is used in the formula E = hf to relate energy and frequency?

• Avogadro's number

• Planck's constant

• Gravitational constant

• Boltzmann constant

How is the frequency of a wave related to its speed and wavelength?

• f = c/λ

• f = λ/c

• f = λc

• f = cλ

What is the first step in calculating the wavelength of a photon from its energy?

• Convert energy to joules

• Measure the speed of light

• Determine the Planck constant

• Calculate the frequency

What is the wavelength of a photon with an energy of 4.9 eV?

• 254 nm

• 688 nm

• 700 nm

• 460 nm

Which range of wavelengths corresponds to the visible spectrum?

• 700-1000 nm

• 390-700 nm

• 1000-1500 nm

• 200-350 nm

What happens to an atom when it absorbs energy and becomes excited?

• It emits light of the same color

• It becomes stable

• It emits light of a different color

• It loses energy