what are the quantities of tera (T), giga (G), mega (M), kilo (k),deci(d), centi(c), milli (m), micro (µ), nano (n), pico (p), femto (f)
Tera (T) = 10^12
Giga (G) = 10^9
Mega (M) = 10^6
kilo (k) = 10^3
deci (d) = 10^-1
centi (c) = 10^-2
milli (m) = 10^-3
micro (μ) = 10^-6
nano (n) = 10^-9
pico (p) = 10^-12
femto (f) = 10^-15
what are the symbol of protons, nucleons, chemical symbol
protons: Z
nucleons: A
Chemical symbol: X
How to draw an atom in physics
The nucleus needs to draw to see protons and neutrons orbiting by electrons
What is the specific charge, and what is the formula for it
charge per unit mass for a particle, nucleus, or ion.
specific charge = charge to mass ratio = Q/m
charge/mass and unit is Ckg-1
What is the photoelectric effect?
-A light shines on a metal and electrons are emitted
-only emitted if the frequency is above the threshold frequency
-The intensity of light has no effect
-speed of electrons travel when leave the metal depends on the colour (frequency) not the intensity
-increase brightness increases the number of electrons emitted per second if only its already being released
What is the symbol of the speed of light and what is it
c: speed of light: 3×10^8m/s
What is work function and its symbol
Minimum energy of (a photon) needed to remove an electron from the surface of the metal
symbol: Φ
how to calculate and explain the extra kinetic energy of electron
-If energy of photon > work function: the extra energy becomes the kinetic energy of the electron
equation: hf (Energy of photon) = Φ(work funtion) + EKmax
what happends if frequency of light = threshold frequency (f0) and what euqation like to it
-energy of photon just enough to remove an electron
-so Ek(kinetic energy) = 0 => energy of photon = work funtion,
euqation: Φ = hf0
what is the equation of the straight line a in Ekmax and frequency graph of photoelectric effect
Ek = hf -Φ(hf0)
what is the symbol of stopping potential
Vs
What is eVs and its unit
-maximum kinetic energy of the emitted electron in the photoelectric effect
-Unit: Joules
-eVs = Ek
What is electrovolt, its symbol
-energy an electron gains when it moves through 1 volt of electric potentia
How to find the Maximum kinetic energy through Vs(stopping potential)
Ekmax = eVs
e (Q) = charge of an eletrcon
v = voltage to stop the strongest/fastest electron
what is a validated evidence
experiment must be repeatable by other independent sciencetist
what is an excited atom
when an electron gains energy and moves up one or more energy levels
how can atomic electron can gain electron
collision with another particle or absorption of one photon (with exacly the right energy)
explain the quantum jumping, when does it move up when does it move down
-Move up: gain energy
-Move down: losing energy by emitting 1 photon with exactly the erngy diffreence between 2 levels
how does Fluorescent Tube produce light
-Electric current passes through the tube containing low pressure mecury
-Electrons collide with mercury atoms → mercury atoms get excited.
-then it dexcite and return to the original shell and emits Uv liggt
-Phosphor coating absorbs UV → emits visible light (fluorescence).
