electromagnetic radiation

Q: What are the three key characteristics of electromagnetic waves?

A: Wavelength (distance between peaks), Frequency (cycles per second), and Speed (how fast the wave travels, c = 3.00 × 10⁸ m/s).

Q: How does wavelength relate to energy and frequency?

A: Long wavelengths have low frequency and low energy; short wavelengths have high frequency and high energy due to the inverse relationship in c = λν.

Q: What is meant by electromagnetic radiation being quantized?

A: Energy is transferred in discrete packets called quanta or photons; not continuously, meaning it comes in specific energy "chunks."

Q: What is a photon and how is its energy calculated?

A: A photon is a particle of light. Its energy is calculated by E = hv or E = hc/λ, where h is Planck’s constant and λ is wavelength.

Q: What is Planck’s constant and why is it important?

A: h = 6.626 × 10⁻³⁴ J·s. It quantifies the relationship between energy and frequency in quantum physics.

Q: How does the wave equation relate wavelength, frequency, and speed?

A: The wave equation is c = λν, where c is the speed of light, λ is wavelength, and ν is frequency.

Q: What is wave-particle duality?

A: It means that particles like electrons exhibit properties of both waves and particles, shown by diffraction and interference patterns.

Q: What did JJ Thomson and George Thomson discover?

A: JJ Thomson discovered the electron as a particle; George Thomson showed electrons also have wave-like behavior.

Q: What is de Broglie’s hypothesis?

A: That all matter, including electrons, exhibits wave-like properties, leading to the concept of matter waves.

Q: What is the emission spectrum and what causes it?

A: It's a series of colored lines produced when electrons fall from higher to lower energy levels, emitting photons.

Q: How is an absorption spectrum different from an emission spectrum?

A: Absorption spectrum shows dark lines where specific wavelengths are absorbed by electrons jumping to higher energy levels.

Q: How are flame tests used to identify elements?

A: Different elements emit characteristic colors when their electrons are excited and return to ground state—useful in identifying them.

Q: What does the Bohr model of the atom propose?

A: Electrons orbit the nucleus in fixed energy levels and only gain/lose energy by jumping between these levels.

Q: How does the Bohr model explain spectral lines?

A: SpQ: What are the three key characteristics of electromagnetic waves?

Q: How does wavelength relate to energy and frequency?

A: Long wavelengths have low frequency and low energy; short wavelengths have high frequency and high energy due to the inverse relationship in c = λν.

Q: What is meant by electromagnetic radiation being quantized?

A: Energy is transferred in discrete packets called quanta or photons; not continuously, meaning it comes in specific energy "chunks."

Q: What is a photon and how is its energy calculated?

A: A photon is a particle of light. Its energy is calculated by E = hv or E = hc/λ, where h is Planck’s constant and λ is wavelength.

Q: What is Planck’s constant and why is it important?

A: h = 6.626 × 10⁻³⁴ J·s. It quantifies the relationship between energy and frequency in quantum physics.

Q: How does the wave equation relate wavelength, frequency, and speed?

A: The wave equation is c = λν, where c is the speed of light, λ is wavelength, and ν is frequency.

Q: What is wave-particle duality?

A: It means that particles like electrons exhibit properties of both waves and particles, shown by diffraction and interference patterns.

Q: What did JJ Thomson and George Thomson discover?

A: JJ Thomson discovered the electron as a particle; George Thomson showed electrons also have wave-like behavior.

Q: What is de Broglie’s hypothesis?

A: That all matter, including electrons, exhibits wave-like properties, leading to the concept of matter waves.

Q: What is the emission spectrum and what causes it?

A: It's a series of colored lines produced when electrons fall from higher to lower energy levels, emitting photons.

Q: How is an absorption spectrum different from an emission spectrum?

A: Absorption spectrum shows dark lines where specific wavelengths are absorbed by electrons jumping to higher energy levels.

Q: How are flame tests used to identify elements?

A: Different elements emit characteristic colors when their electrons are excited and return to ground state—useful in identifying them.

Q: What does the Bohr model of the atom propose?

A: Electrons orbit the nucleus in fixed energy levels and only gain/lose energy by jumping between these levels.

Q: How does the Bohr model explain spectral lines?

A: Spectral lines result from energy released as electrons transition from higher to lower energy levels.

Q: What is the formula for energy change in hydrogen transitions?

A: ΔE = 2.178 × 10⁻¹⁸ J × (1/n²final – 1/n²initial), which calculates the energy of electron transitions in hydrogen.

Q: Why is the Bohr model limited in explaining atoms?

A: It accurately describes hydrogen but fails for multi-electron atoms because it doesn’t account for electron-electron interactions.

Q: What do bright lines in hydrogen's emission spectrum represent?

A: Specific photon energies released when electrons fall to lower energy levels—each line corresponds to a unique transition.

Q: What is the speed of light and its significance?

A: The speed of light is 3.00 × 10⁸ m/s; it's a fundamental constant in physics used to relate energy, frequency, and wavelength.

ectral lines result from energy released as electrons transition from higher to lower energy levels.

Q: What is the formula for energy change in hydrogen transitions?

A: ΔE = 2.178 × 10⁻¹⁸ J × (1/n²final – 1/n²initial), which calculates the energy of electron transitions in hydrogen.

Q: Why is the Bohr model limited in explaining atoms?

A: It accurately describes hydrogen but fails for multi-electron atoms because it doesn’t account for electron-electron interactions.

Q: What do bright lines in hydrogen's emission spectrum represent?

A: Specific photon energies released when electrons fall to lower energy levels—each line corresponds to a unique transition.

Q: What is the speed of light and its significance?

A: The speed of light is 3.00 × 10⁸ m/s; it's a fundamental constant in physics used to relate energy, frequency, and wavelength.