Physical Science Final Study Guide

CHAOTER 17 & 18:

Wave: disruption that carries energy from one location to another

Mechanical Wave: a wave that moves through a physical medium and carries energy by disrupting the matter of the medium

Electromagnetic Wave: disruptions in an electromagnetic field that can travel through the vacuum of space, without a physical medium

Simple Harmonic Motion: periodic motion that is caused by a restoring force that is proportional to its displacement

Transverse waves: waves in which the disruption moves perpendicular to the direction of wave travel

Longitudinal waves: when the disruption occurs parallel to the direction of wave movement

Surface waves: occur along the surface between two mediums, moves both parallel and perpendicular to the direction of wave travel.

         -water is a type of surface wave 

Refraction: a change in wave direction due to a change in a wave’s speed as it enters a new medium

Reflection: bouncing of waves of waves off a surface

Diffraction: the bending of waves around an obstacle or through an opening

Doppler effect: the apparent change in frequency of a wave due to the motion of the source or the receiver

Sound waves: a type of energy that can be transmitted as waves through a medium. (aka mechanical)

            -sound waves or LONGITUDINAL waves

Variables that affect the speed of sound: 1) density of air, 2) medium, 3) temperature

Sound travels fastest through solids, then liquids, and slowest in gasses

As the density of the gas increases, the speed of sound decreases

As temperature increases, speed of sound increases (they’re proportional)

Sonography: uses ultrasound to create images of objects found inside other objects (what they use to see babies in the womb)

Period: the time interval for the motion to repeat

Frequency: the number of waves, or cycles that occur each second

Crest: the highest point of each wave

Trough: halfway point between two crests, lowest point of a wave

Wavelength: the length of a wave is the distance between two identical points on a successive wave

Amplitude the maximum displacement (vertical distance) from the undisturbed or equilibrium position

Wave height: vertical distance between the trough and crest

CH 19 & 20:

Electrical charge depends on the movement of electrons

Like forces repel, opposite attract (golden retriever and black cat energy) ((im lonely))

Static electricity: accumulated electric charge on an object

Current electricity: electricity involving moving electric charges

DC current: electricity can flow in one direction, batteries

AC current: changing or alternating of the direction of movement of the charge carriers

Electrical conductors: materials through which charge moves easily

Electrical insulators: a material through which charge flows poorly

Voltage: the “force” that moves electric charge carriers through an electric current

Resistance: the property of matter indicating the degree to which the material slows down the flow of charge carriers

Current: movement of electric charge through a complete loop

Factors that affect the resistance in a wire: temperature of a material, length of a wire, diameter of a wire, material’s resistivity

Magnetic field lines flow from the north into the south

Earth’s magnetic field is terrible (the summary): The earth’s “Magnetic North Pole” is relatively close to its geo north pole but is TECHNICALLY a magnetic south pole. Who knows why tf someone made it like that. and it’s vice versa for the south pole. So the “magnetic south pole” is a magnetic north pole :skull:

Electromagnetic properties: electric current in a wire creates a magnetic field, and vice versa

Right hand rule: f you point your pointer finger in the direction the positive charge is moving, and then your middle finger in the direction of the magnetic field, your thumb points in the direction of the magnetic force pushing on the moving charge.

CH 21 & 22

Electromagnetic waves/radiation: disruptions in an electromagnetic field that, unlike mechanical waves, can travel through the vacuum of space, carries energy

Speed of electromagnetic waves in a vacuum is c=3.00 x 10^8 m/s

c=fλ: velocity for electromagnetic waves in a vacuum

E = hλ, h=planck’s constant: states that energy is proportional to frequency

FREQUENCY AND WAVELENGTH ARE INVERSELY PROPORTIONAL (as f goes up, w goes down)

photon: massless particle, bundle of electromagnetic energy

wave-particle duality: electromagnetic energy travels as both waves and particles

Electromagnetic spectrum: the collection of all electromagnetic waves

electromagnetic spectrum from lowest to highest frequency: radio, micro, infrared, visible light, ultraviolet, xray, gamma

electromagnetic spectrum from longest wavelength to shortest: radio, micro, visible light, infrared, uv, xray, gamma

luminous objects: those that can produce visible light

Incandescence: produce by objects that flow as a result of high temperature

Fluorescence: a material gives off visible light after absorbing electromagnetic energy

Phosphorescence: like fluorescence, but slower

Chemiluminescence: chemical reactions that give off energy in the form of light (bioluminescence is a type of this)

Transparent: light can easily pass through

Translucent: light cannot easily pass through

Opaque: visible light cannot pass through

the luminous/additive (light) primary colors: red, blue, green. when mixed they create white

illuminated/subtractive primary colors: cyan, magenta, yellow. when mixed they create black

subtractive colors reflect light, the color we see depends on what wavelength of light it reflects

CH 3

Quantum Mechanical Model: most recent atomic model in which electrons are found in orbitals that are positioned around a nucleus that contains protons and (usually) neutrons

Bohr model: distinct, spherical orbits at a fixed distance from the nucleus, not random, only in distinct energy levels

Subatomic particles and sizes: electrons: much much smaller than protons and neutrons, protons: much larger than electrons?, neturons: about the size of one proton and an electron

Atomic number: amount of protons in an element

Mass number: total number of particles in the nucleus (ex: isotope carbon-12, 12 is the mass #)

atomic mass: weighted average of the masses of all naturally occurring isotopes of that element

Isotopes: atoms of the same element with different numbers of neutrons

Isotope notation: massnumber/atomic number element name

Ions: charged atoms

anions: ions with a negative charge

Cations: ions with a positive charge

CH 4

Mendeleev left SPACES :shock: :mindblown: :holycow??: which led to other scientists knowing where to search 

HOW MANY GROUPS/FAMILIES?: 18

HOW MANY PERIODS?: 7

The family/group # (starting from 13-18) tells how many valence electrons are in the elements final valence shell

-ex: an element in group 17 (Cl) will have 7 valence electrons in its final shell 

*EXCEPTIONS: Helium and and hydrogen only need 2*

Know the different categories (noble gasses, alkali metals, etc) ((im not putting all that))

Period # indicates how many energy levels there are 

-ex: an element in period 3 (Mg) will have 3 energy levels

Know electron dot notation (how am i supposed to make that a term?)

Electronegativity: the measure of an element’s ability to attract and hold electrons when bonded to other atoms 

As an atom’s radius increases, have less electronegativity, as there’s more distance between the particles. When the radius is smaller, and the electrons are closer to the nucleus, the pull is stronger. 

Moving across the period=more electronegativity 

Moving down column=less electronegativity 

CH 5

Chemical bond: an electrostatic attraction that forms between atoms when they share or transfer valence electrons, they bond to gain stability

Octet rule: atoms are stable when they have 8 valence electrons in their valence shell

-exceptions: hydrogen and helium (not these mfs again, they think they’re so special), lithium berylium and boron too but im not too sure why 

Covalent bond: a chemical bond formed as the result of two atoms sharing electrons

Ionic bond: between a metal and nonmetal, (cation and anion), they TRANSFER electrons

Metallic bond: attraction between metal atoms and their sea of shared electrons

WHEN WRITING CHEMICAL FORMULAS: use subscripts after elements to tell how many of each kind of element their is, 

THE GREEK PREFIXES FOR COVALENT BONDS: 1: mon, mono, 2. Di, 3. Tri, 4. Tetra, 5. Quint, 6. Hex, hexa 

\n

CHAPTER 7: 

Why do we balance? To fulfill the law of conservation of matter. Where would all the extra atoms go ???!?!?! (true meaning: the class tells us to)

Mole: 6.022 x 10^23 particles of any substance

Synthesis reaction: two or more reactants combine to form a single product, x+ y →xy

Decomposition reaction: single reactant breaks down into two or more products, xy → x+y

Single replacement reaction: one element in a compound is replaced by another, xy + z → xz+y

Double replacement reaction: two compounds swap cations or anions, xy +za → xa + zy

Combustion: a fuel substance reacts with oxygen, x + o2 → co2 + h2o

Exothermic reaction:  reactions that release more energy than they absorb, combustion is example

Endothermic reaction: reaction that absorbs more energy than it exerts

Activation energy: amount of energy needed to start a reaction

\n

CH 8: 

Radioactivity: spontaneous emission of particles and energy from an atom’s nucleus

Alpha decay: alpha particles are made of two protons and two neutrons, radiation can be stopped by a sheet of paper

Beta Decay: negative charge, relatively hard to stop?? (idk the definitions ill fix it later)

Gamma Decay: no change to composition in nucleus

\n \n