lenz's law and minor clarifications

diff --git a/physics/light-matter.md b/physics/light-matter.md
index 6eed91fd38e83d45b7ff1c3743a49d38284f63f9..ce114bac8b0daeddb34a5c65ac2b632fb06d4adb 100644 (file)
--- a/physics/light-matter.md
+++ b/physics/light-matter.md
@@ -46,6 +46,7 @@ particle model:
 - rate of photoelectron release is proportional to intensity of incident light
 - shining light on a metal "bombards" it with photons
 - no time delay
+- one photon releases one electron
 
 #### Work function and threshold frequency
 
@@ -68,9 +69,13 @@ $f$ is frequency of incident photon (**not** emitted electron)
 $\phi$ is work function ("latent" energy)
 
 Gradient of a frequency-energy graph is equal to $h$  
-y-intercept is equal to $\phi$
+y-intercept is equal to $\phi$  
+voltage $V$ in circuit is indicative of max kinetic energy in eV
 
 #### Stopping potential $V_0$
+
+Smallest voltage to achieve minimum current
+
 $$V_0 = {E_{K \operatorname{max}} \over q_e} = {{hf - \phi} \over q_e}$$
 
 ## Wave-particle duality
@@ -105,7 +110,8 @@ $$\rho = {hf \over c} = {h \over \lambda}$$
 
 
 ### Absorption
-- Black lines in spectrum show light not reflected  
+- Black lines in spectrum show light not reflected
+- Frequency of a photon emitted or absorbed can be calculated from energy difference: $E_2 – E_1 = hf$ or $= hc$
 
 ### Emission
 
@@ -166,6 +172,17 @@ Therefore, position and velocity cannot simultaneously be known with 100% certai
 
 **Quantum mechanical model** - electron clouds rather than discrete shells (electrons are not particlces). We can only calculate probability of an electron being observed at a particular position
 
+Newton's and Einsteins models work together  
+
+### Photon-electron interaction
+
+When a photon collides with an electron, momentum is transferred to electron.
+
+$$\rho_{\text{photon}}={h \over \lambda}$$
+$$E=\rho c$$
+
+
+
 
 
 774 abc melbourne
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