Parts Of An Atom
Protons:
# of Protons = Atomic Number
Neutrons:
# of Neutrons = Mass Numbers* - Atomic Number
* You need to the round off the Mass Number to the nearest whole number
Atomic Mass:
Atomic Mass: Neutron + proton = electron
Bohr- Rutherford diagrams:
The number of electrons per shell 2,
8, 8, 16. The outer shell is called valence electrons.
Valence electrons: All valence electrons want to be stable. In order
for that to happen it must either lose electrons or gain electrons.
Standard Atomic Notation
Standard atomic notation:
:
Elements:
Periodic table of elements
H: Hydrogen
He: Helium
Li: Lithium
Be: Beryllium
B: Boron
C: Carbon
N: Nitrogen
O: Oxygen
F: Fluorine
Ne: Neon
Na: Sodium
Mg: Magnesium
Al: Aluminum
Si: Silicon
P: Phosphorous
S: Sulphur
Cl: Chlorine
Ar: Argon
K: Potassium
Ca: Calcium
Compounds:
2 atoms joined together, this is called a chemical bond.
Ex: Na+1 and Cl -1 = NaC1
Ions:
Anion: Negative charge
Cat ion: Positive charge
- Atoms will either gain or lose electrons in order to have the same number of
electrons as a Noble gas.
Ex: Aluminum atoms have 13 electrons. This atom can either LOSE 3 electrons as the noble gas Neon or the atom can GAIN 5 electrons to end up with the same number of electrons as the Noble gas Argon. But which one will it do? WHICHEVER OF THE NUMBER IS SMALLER.
** Note: when a Bohr Rutherford diagram loses electrons it becomes positive when it gains it becomes negative!
Ionic compound: Ex; B-2 O+2
= B-2 O+2
= B2O2
= BO <-- Name of this Ionic compound is Boron Oxide.
Ionic Names: Nitrogen – Nitride
Oxygen – Oxide
Fluorine – Fluoride
Phosphorus – Phosphide
Sulphur – Sulphide
Chlorine – Chloride
Bromine – Bromide
Iodine – Iodide
* When naming the the ionic compounds Metals are the first word then the second word will be the Nonmetals.
Periodic Table
Periodic Table:
Groups – Go up and down on a periodic table. (Going vertically down)
Periods – Goes side to side. (Going horizontal)
Alkali Metals:
Location on the Periodic Table
The alkai metals are the elements located in Group I of the periodic table,
Properties
- The alkai metals are highly reactive. They react readily with nonmetals, particularly halogens.
- Alkali metals have on electron in their outer shell, which is loosely bound. An alkali metal can easily lose its valence electron to form a cation.
- The alkali metals exhibit many of the physical properties common to metals, although their densities are lower than those of other metals.
Alkali Earth Metals:
Location on the Period Table
The alkaline earths are the elements located in Group 2 of the periodic table.
Properties
- The alkaline earths are highly reactive
- The alkaline earths have two electrons in ther outer shell. The two valence electrons are not tightly bound to the nucleus, so the alkaline earths readily lose the electrons to form cations
- The alkaline earths possess many of the characteristic properties of metals.
Halogens:
Location on the Period Table
The halogens are located in Group 17 of the periodic table.
Properties
- Most reactive non-metals and almost always occur as a compound naturally
- These reactive nonmetals have seven valence electrons. In a chemical reaction halogens will gain one electron to have a stable arrangement
- The halogens are particularly reactive with the alkali metals and alkaline earths, forming stable ionic crystals.
Noble Gases:
Location on the Periodic Table
The noble gases, also know as the inert gases, are located in Group 18 of the periodic table.
Properties
- The noble gases are relatively nonreactive. They almost never forms a chemical compound with other elements
- The elements has a stable arrangement of electrons, this is because they have a complete valence shell. They have little tendency to gain or lose electrons
- Examples: He, Ne, Ar
- The noble gases have a low boiling points and are all gases at the room temperature.
Isotopes
Isotopes:
Any of two or more forms of an element, wach with the same number of protons but with different numbers of neutrons.
The name of radioactive isotopes has been shortened to: Radioisotopes
Physics: Static and current electricity
Law of Electric charges:
1.Neutral charges attract charged objects
2.Like charges repel each other
3.Opposite charge attract each other
Charging by friction:
When two objects rub against each other
Creates static build up
Many of the effects cause by static electricity
During the transfer only electrons move
Charging by contact:
transferring an electric charge from one substance to another by touching.
Charging by Induction:
Charging an object without direct contact.
Conductors:
Conducts electricity
Atoms can move freely
Good insulators: Metals (Gold, Platinum, Copper) & humid air.
Insulators:
Protection from electric shocks
Have strong hold on electrons, this causes static build up
Electrons cannot move freely from one atom to another atom
Good Insulators: Plastic, wood, rubber, & dry air
Current: The rate of which electrons go by each second.
- Units: Amps
- Device: Amp meter
Potential difference: Measures electric potential between two points in a circuit.
- Units: V
- Device: Voltmeter
Resistance: Measures how it slows the flow of electrons.
Units: Ohms
Series & Parallel:
- In a series circuit there is only one way for the electrons to flow.
- In a parallel circuit there is more than one way for the electrons to flow.
Type of circuit: ll current: ll Potential diff. ll Resistance:
Series ll same throughout the ll Shared b.w loads II more load reduces current
Circuit
Parallel ll Shared b.w paths ll same through all paths II More current to flow
Ohms Law:
If voltage is increased, current increases and resistance does no change.
If resistance is increased, current decreases if the voltage does not change.
Current: Amps / I
Resistance: Ohms
Voltage: Volts/ V
Power:
Formulas:
&& P= E over time
Power is measured in watts
Electrical Energy:
Formula: E= V x I X t
Electrical energy is measured in Joules (J)
Voltage is measured in volts (V)
Current is measure in amps (I)
time is measured in seconds (S)
Percent Efficiency:
% efficiency = useful energy output x 100%
total energy input
Cost calculations:
For cost calculations , units must be E= kW° h
Cost = rate x amount of energy used
Rate is measure in cent \ kW °h
Energy is measured in kW°h
Conversions:
1000w.h = 1 kw.h
1000w = 1kw
1hr = 3600s
1hr = 60mins
1mins = 60s
Generating Electricity -> On a seperate paper
Space
Terms:
Astronomy:
The study of what is beyond Earth.
Universe:
Everything that exist, including all matter and energy everywhere.
Galaxy:
A large huge collection of gas, dust, and hundreds of millions of stars and planet.
Solar System:
The Sun and all the objects that travel around it, including the nine known planets and the moons of those planet.
Star:
A large collection of matter that emits huge amounts of energy.
Planet:
A large piece of matter, generally spherical, that revolves around a star.
Comet:
A chunk of ice and dust that travels in a very long orbit around the sun.
Meteor:
A bright streak light across the sky caused by a meteoroid.
Moon:
Is a natural satelliet that moves around a planet.
Sunspot:
Is a region on the Sun's surface that is cooler than the surrounding areas
Solar Flares:
Is a massive explosion at the surface of the sun.
Rotation and Revolution
Rotation:
Spinning of an object around it's own axis.
-> One rotation of the Earth takes 24 hr = to 1 day
-> The axis of the Earth is tilted at an angle of 23.5 degree
Revolution:
Is one complete orbit of an object around the Sun, a journey of one year.
-> It takes for the Earth to revolve once around the Sun about 365.25 days.
-> Where ever the axis is tilted at the Sun thats what seasons it is for that part of the hemisphere.
-> When the northern hemisphere is tilted toward the sun, this creates summer in the northern hemisphere.
Moon Phases
Solar Eclipse
Lunar Eclipse
