Desk Name Date Atomic Spectra r-lah and Atomic Structure Questions Before beginn

Question

Desk Name Date Atomic Spectra r-lah and Atomic Structure Questions Before beginning this experiment in the laboratory, you sh following questions. should be able to answer the . Name the colors of visible light beginning with that of lowest 2. Distinguish between absorption and emission of energy 3. A system proposed by the U.S. Navy for underwater submarine communication, called ELF (for extremely low frequency), operates with a frequency of 76 Hz. What is the wavelength of this radiation in meters? In miles? (I mile 1.61 km) 4. What is the energy in joules of the frequency given in question 3? 5. Red and green light have wavelengths of about 650 nm and 490 nm, respectively. Which light has the higher frequency -red or green? Which light has the higher energy-red or green 6. Mg emits radiation at 285 nm. C ould a spectroscope be used to detect this emission? 87

Explanation / Answer

1. Colours of visible light in increasing order of energy and decreasing order of wavelength is as follows: ( inside brackets is visible light)

Infrared<( Red <Orange<Yellow<Green<Blue<Indigo<Violet)< Ultraviolet

2. Absorption of energy is when a energy from a photon ( of light) is taken by electrons of any atom. thus, electromagnetic energy changes to internal energy of absorber.

Emission of energy happens when an atom or molecule makes a transition from higher energy to lower energy level. Energy is released in form of distinct quanta.

3. Frequency= 76 Hz

we know that for electromagnetic radiation, frequency= c/ wavelength

where c is speed of light 3 * 10^8 m/s.

then, wavelength= 3*10^8 m/s / 76 Hz

=> 3.9 * 10^6 m => 3.9 * 10^3 km => 2.4 * 10^3 miles

4. We know, for electromagnetic radiation,

Energy = h * frequency

where h is plancks constant

E = 6.26 * 10^-34 m2 kg/s * 76 Hz

=> 475.76 * 10^-34 Joule

Related Questions

Navigate

• Browse (All)
• Browse D
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.