Grade 11 - Physics Semester 1

Kinetic Particle Model (KPM) states

Kinetic 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

0<Z<10, N\=Z, therefore its stable
Z\>10, N/Z increases, to ensure stability

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