physical science eoct review
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Physical Science EOCT Review. Milton High School. Atomic number – number of protons ; identifies the element Atomic mass – number of protons plus the number of neutrons in the nucleus of atom (protons + neutrons) Protons = positive charge Neutrons = no charge Electrons = negative charge - PowerPoint PPT PresentationTRANSCRIPT
Physical Science EOCT Review
Milton High School
Atomic number – number of protons; identifies the elementAtomic mass – number of protons plus the number of neutrons in the nucleus of atom (protons + neutrons)
Protons = positive chargeNeutrons = no chargeElectrons = negative charge
You can know the number of electrons because in neutral atom the number of electrons is the same as the number of protons
If the atomic number for arsenic is 33 and the atomic mass is 75 then:
How many protons does arsenic have?
How many neutrons can you find in the nucleus of the arsenic-75?
How many electrons in arsenic’s electron cloud?
33
42
33
What is an isotope?
Isotopes = atoms with different number of neutrons
Fusion or FissionFusion = joining together two nuclei; example the Sun
Fission = splitting apart of atoms; such as in nuclear reactor plants
Fission
Phase change – occur as a result of energy being added or taken away from matter
As temperature rises, matter moves to a more rapid state
Force = mass x acceleration
F = ma
If F = 100 N and m = 50 kg;
what is the dog’s acceleration?
100 N = 50kg (a)
100 N /50kg = a
2 m/s2 = a
Mass vs. Weight
Weight = mass x gravity
Newton’s First Law of MotionAn object at rest will remain at rest and an object in motion
will remain in motion unless acted on by an outside net force; objects tend to keep doing what they are doing
Newton’s First Law of Motion
Newton’s Second Law of Motion
change of velocity, or
acceleration, is related to the mass of
the body and the force applied
Newton’s Third Law of Motion
For every action, there is an equal and opposite reaction
Work = Force x Distance
If the blonde boy does not make the rock move is he doing any work?
NO…you need distance
More Physics
• Speed = distance/time
• Velocity is speed in a particular direction
• Acceleration is change in velocity/time elapsed
Waves
Electromagnetic Spectrum
Long wavelength = low frequencyShort wavelength = high frequency
Electromagnetic waves do not need to travel through a medium
Speed of Sound – depends on the medium it passes through
Sound cannot pass through a vacuum – no molecules present
Sound waves travel faster at higher temperatures and density
Sound travels faster through a solid and slower through a gas
Reflection
Angle of incidence is equal to angle of reflection
Refraction – bending of waves due to a change in speed
Diffraction- bending of waves around a barrier (all waves can be diffracted)
Interference – when two waves meet while traveling through the same medium
(a) Constructive (b) Destructive
Electricity•Electricity – flow of electrons
•Voltage – amount of energy available to move electrons
•Current – rate of electron flow
•Resistance – hindering electron flow
Electricity
• Voltage = current x resistance
V = IR
Electromagnets
More turns of copper wire = stronger magnetic field