Light as a wave and as a particle
Grade 11 Science Worksheet - Challenge Me
Circle the best answer, or write your answer on the line.
The CRC Handbook gives copper a work function of 4.7 eV. With hc = 1239.84 eV·nm, what is the longest wavelength that frees electrons, to 0.1 nm, Ari?
In a double-slit pattern, what makes a bright band, Jun?
- One slit being brighter
- Light bouncing off the screen
- Waves arriving in step
Very dim light sends photons through two slits one at a time. What builds up on the screen over time, Kira?
- Two plain bright lines
- An even glow
- The same bright and dark bands
One of the two slits is covered. What happens to the bands, Luz?
- The bands go away
- They double in number
- They get sharper
Milo says bright enough red light will free electrons from any metal. Agree or disagree?
- Disagree: red photons may be too weak
- Agree: bright light works on any metal
- Agree: brightness adds energy to each photon
Noah says doubling the brightness of light on cesium doubles each electron's greatest energy. Agree or disagree?
- Agree: brighter light gives faster electrons
- Disagree: it doubles the number of electrons
- Agree: energy doubles with brightness
Pia says the photoelectric effect proves light is never a wave. Agree or disagree?
- Disagree: light also shows wave interference
- Agree: particles can't interfere
- Agree: waves can't free electrons
Ultraviolet light of 250 nm shines on copper (work function 4.7 eV). Are electrons freed, Ren?
- Yes: each carries about 4.96 eV
- No: copper can't free electrons
- No: 250 nm is too long
Light of 300 nm and light of 600 nm are compared. How do their photon energies compare, Tala?
- They are equal
- The 300 nm photons carry twice as much
- The 600 nm photons carry twice as much
Infrared photons of about 1 eV shine on cesium (2.1 eV). What happens, Zee?
- Electrons leave with 1.1 eV
- No electrons are freed
- Electrons leave with 3.1 eV