Ch.7 - Quantum MechanicsWorksheetSee all chapters
All Chapters
Ch.1 - Intro to General Chemistry
Ch.2 - Atoms & Elements
Ch.3 - Chemical Reactions
BONUS: Lab Techniques and Procedures
BONUS: Mathematical Operations and Functions
Ch.4 - Chemical Quantities & Aqueous Reactions
Ch.5 - Gases
Ch.6 - Thermochemistry
Ch.7 - Quantum Mechanics
Ch.8 - Periodic Properties of the Elements
Ch.9 - Bonding & Molecular Structure
Ch.10 - Molecular Shapes & Valence Bond Theory
Ch.11 - Liquids, Solids & Intermolecular Forces
Ch.12 - Solutions
Ch.13 - Chemical Kinetics
Ch.14 - Chemical Equilibrium
Ch.15 - Acid and Base Equilibrium
Ch.16 - Aqueous Equilibrium
Ch. 17 - Chemical Thermodynamics
Ch.18 - Electrochemistry
Ch.19 - Nuclear Chemistry
Ch.20 - Organic Chemistry
Ch.22 - Chemistry of the Nonmetals
Ch.23 - Transition Metals and Coordination Compounds

Solution: The work function for chromium metal is 4.37 eV. What wavelength of radiation must be used to eject electrons with a velocity of 2500 km/s?

Problem

The work function for chromium metal is 4.37 eV. What wavelength of radiation must be used to eject electrons with a velocity of 2500 km/s?

Solution

We’re being asked to determine the wavelength of radiation (light) that must be used to eject electrons from a chromium metal. 

When photons with enough energy hit the surface of a metal, electrons are emitted. This phenomenon is known as the Photoelectric Effect.


Total energy (ΔE) in photoelectric effect can be calculated using the following equation:

E=Ework function+EKE of electron


Where:

Δis the total energy or the energy of the light/photon/radiation and can be calculated using the equation:

E=hν

Etotal energy = J
h = Planck’s constant = 6.626x10-34 J
s
ν = frequency = Hz or s-1

Ework function is the work function or threshold frequency of the metal (minimum energy required to remove an electron from the metal)

Solution BlurView Complete Written Solution