Studied by 21 peopleKinetic Particle Model (KPM) states
that all particles are constantly moving.
Theoretically, at absolute zero
particles are not vibrating and have no energy.
Absolute Zero (Zero Kelvin)
-273.15°C
Thermal energy is
internal energy of an object due to kinetic energy.
The more thermal energy means
The higher the temperature
Temperature is
measurement of an average kinetic energy of an object system.
Kinetic energy is
energy of movement, based on work required for an object to move between 2 points.
Heat is
thermal energy that transfers from a 'hot body' to a 'cold body'
Internal energy is
kinetic energy (K.E) + potential energy (P.E) = K.E & P.E
Conduction is
heat is transferred through contact between particles. A higher vibrating gives energy to a lower vibrating particle.
Convection is
bodies or currents of particle redistribute due to density. A fluids heat up they expand and get less dense.
Radiation
heat energy is transferred as wave energy (electromagnetic waves). It may transfer through a vacuum.
The addition of energy into a system (no phase change) invokes a
transformation to kinetic energy of particles.
An increase in particle vibration (energy) means
an increase in temperature
Phase change is
change of materials state, eg; solid liquid or gas.
All vibrating particles
emit radiation
If vibration increases, then
the radiation output initially increases, however it will vary.
If energy absorbed is less than energy emitted then
potentially, heat loss has occurred.
Energy removal/loss can occur through
conduction, convection, and radiation.
Specific heat capacity is
the amount of energy required to heat 1kg of a material by 1°C.
Direct proportionality is
Q ∝ m, where m=mass and Q= heat energy.
Explain Q ∝ m
when m changes, Q changes in the same way.
If something has a higher heat capacity then
more heat energy is needed
Explain the process of phase changes
When matter changes state (solid, liquid, gas) molecular bonds are restructured. the bond restructuring requires energy for bonds and forces to form/breakdown/rearrange. While this occurs, additional energy does not affect the average kinetic energy, thus the heat energy, meaning there is no temperature change. The process of changing state/ phase change requires energy gain/ loss as the material/ medium has a change in P.E.
Latent heat is
hidden energy, which is unique for every material/ medium. This is the required P.E during phase change.
Calorimetry is
the process of measuring the amount of heat released or absorbed during a chemical reaction.
The Zeroth law states that
objects in thermal contact will eventually reach a thermal equilibrium.
All forms of energy has
the ability to transform into another form of energy.
Energy cannot be
created or destroyed
During transformations,
particles undergo a change. At the micro level, bonds and vibration of particles change. At the macro levels object transform by possibly moving, rotating, rolling etc.
Mechanical work is
energy used for the object to transform.
first law of thermodynamics is
energy is always conserved, irrelevant of the transformation. Total energy remains constant. Law of conservation of energy is always obeyed.
In mechanical systems energy is
'lost' to the environment as heat/sound/friction
Efficiency is
how effective a system or action may execute the required operation
Protons and neutrons are _____ times _______ than electrons
2000, heavier
The four main forces are
gravitational force (gravity), electromagnetic force (ESF), strong nuclear force (SNF), weak nuclear force (WNF)
Electromagnetic force is aka
electrostatic (ESF), electro repulsive, or coulomb force
ESF causes protons to
repel
ESF is a
non-contact force
Proton - proton
proton on proton; a way of describing the interaction.
proton-proton and electron-electron interactions are caused by
repulsive force
proton-electron interactions are caused by
attractive force (ESF)
The strongest force is
strong nuclear force
The weakest force is
gravitational force
SNF is
a contact force
fm is a
femtometre, (a quadrillionth of a metre).
SNF overcomes
ESF within 1.5 fm.
SNF only occurs within
the nucleus
When SNF acts within 1.5 fm
larger nuclides become less stable
As protons increase
protons cannot touch each other which causes an imbalance in SNF and ESF, causing the isotope to be unstable.
Neutrons balance out the
stability of nuclides, binding nucleons
Serge plots are
plots of all stable and unstable isotopes.
Serge plots show
If the isotope doesn't have enough neutrons
positrons are emitted from protons, causing the proton to become a neutron
Protons emitting B+ decay, it causes the segre plot to
move left or up
Positrons are
positive leptons
Leptons are
an elementary particle of half-integer spin that does not undergo strong interactions.
As the number of protons increase, an atom becomes
heavier and the ESF increases
When there are too many neutrons,
neutrons emit an excited electron, and becomes a proton
an excited electron is
(e- decay or β- decay)
too many neutrons means that
the nucleus needs to get rid of mass or energy
When neutrons emitting e- decay or β- decay, it causes the segre plot to move
right and down
Heavier isotopes require
more SNF and more neutrons than protons
If N/Z is not a stable nuclide
natural radioactive decay (emission) may occur
Decay includes
alpha decay, beta (+ or -) decay, gamma emission (U1-4) and other forms.
Naturally occurring stable isotopes are
less likely to undergo radioactive decay
Emission includes
energy emission for stability, and sometimes particle emission for stability
A parent nuclide is
nuclide before decay
A daughter nuclide is
nuclide after decay or emission
Neutron emission is when
nucleus mass reduces, however the atomic number doesn't change
Proton lost is when
nucleus mass and atomic number reduces, therefore the particle changes, eg, carbon to boron.
Rounding in exams
the answer should have the same number of digits as the least accurate number in the operation.
Percentage uncertainty is the same as
relative uncertainty
Absolute uncertainty =
1/2 x (increment)
Percentage uncertainty =
(abs unc/ measurement) x 100
The steps for calculating uncertainty of a line with error bars are
calculate the (T=gradient (m) + y-intercept) of the l.o.b.f, minimum line and maximum line. Then calculate the absolute uncertainty of the gradient (Abs Unc Gradient (m) = (max gradient-min gradient)/2). The final equation is then, T = ((l.o.b.f m) ± m)t + ((l.o.b.f) ± Abs Unc of y-int)
What does it mean to find the mathematical relationship
You must calculate the gradient with the formula T=kt, and explain the relationship using x ∝ y.
Absolute Uncertainty formula
max-min/2
Formula for an equation
T = kt, where k is the gradient and t is the y-intercept
Words to describe graph trends
positive, negative, linear, constant rate of change
Formula for absolute zero
0 Kelvin = -273°C
Specific Heat capacity formula
Q = mc∆T
Explain Q=mc∆T
Q = heat energy (if Q>0J, temp increases, if Q<0J, temp decreases) m = mass (kg) c = specific heat capacity (Jkg-10 C-1) ∆T = Tf-Ti (change in temp)
Latent Heat formulas
Q = mLv and Q = mLf
Explain Q=mLv and Q=mLf
Q = heat energy (joules) m = mass (kg) Lv = Latent heat of vaporization (Jkg-1) Lf = Latent heat of fusion (Jkg-1)
Lv and Lf of a substance is
Lv the amount of energy per kg required to change a substance from/to liquid state to/from gas state. Lf is the same except from/to solid to/from liquid state.
Formula for thermal equilibrium
Total energy of Q1 = Total energy of Q2 Q1T = Q2T
To calculate thermal equilibrium, the formula is
∆Q1 = -∆Q2
Formula to calculate the change in internal energy
∆u = Q±W
Formula for efficiency
η = (energy output/energy input) x 100
Symbols, mass and charge of alpha decay
The mass is 2 protons and 2 neutrons, and it has a +2 charge.
Symbols, mass and charge of beta positive decay
The mass is 1 positron, and it has a +1 charge.
Symbols, mass and charge of beta negative decay
The mass is 1 charged electron, and it has a -1 charge.
Symbols, mass and charge of gamma emission
Gamma emission are waves, therefore there is no mass or charge.
Ionisation ability meaning
the capability to remove electrons from atoms and molecules in the matter through which they pass.
Ionisation ability for the decay
From highest to lowest it goes, alpha, beta +, beta -, gamma.
Penetration ability meaning
the power (length) of an electron beam transmitted for a substance.
Penetration ability for decay
from highest to lowest it goes, gamma, beta -, beta +, alpha.
Against gold foil, alpha particles
are blocked/deflected
Against gold foil, beta + and -
have minimal deflection
Note
Flashcard