Physical Science Final SG 2026

static electricity

a charge imbalance that results in the build-up of excess electric charge on an object

electric field

area surrounding charged particles/objects within which a force can be exerts on other charged particles/objects

conductor

materials that allow electrons to easily flow

insulator

materials that block the flow of electrons through them

current

the net movement of electric charge in a single direction

voltage difference

the push (force) that causes charge to move

resistance

the tendency of a material to oppose the flow of electrons through it

ohm’s law

the amount of current is directly proportional to the voltage difference (the higher the voltage, the higher the current; the lower the resistance, the higher the current)

circuit

closed path through which electrons can flow

ammeter

measures amount of current (only in series circuits)

voltmeter

measures the voltage drop (only in parallel circuits)

fuse

small piece of metal within that melts when overheated to open the circuit and prevent current from flowing

circuit breaker

piece of metal that bends when overheated to open the circuit and prevent current from flowing

magnetism

property of some materials that allows them to give off an attractive or repulsive force

magnet

a material that gives off an external magnetic field, making it possible to apply a force over a distance

magnetic field

external force given off by a magnet; strongest at the poles

ferromagnetism

phenomenon where objects placed in a strong magnetic field become magnetized due to the poles within their atoms aligning

differentiate between the effects of an open vs. closed circuit

in a closed circuit, electricity flows and devices can operate, while in an open circuit, the flow of electricity is interrupted, and devices cannot function

ex. calculate the current flowing through the circuit of a toy car that has a resistance of 20 ohms and is powered by a 3-volt battery

0.15 amps

wave

a rhythmic disturbance that transfers energy through matter or space

medium

matter through which a wave travels through can be solid, liquid, or gas

period

the amount of time it takes one wavelength to pass a point

frequency

the number of waves that pass a given point in one second

reflection

when a wave strikes an object and bounces off of it

refraction

the bending of waves caused by a change in its speed as it moves from one medium through another

diffraction

when an object causes a wave to change direction and bend around it

absorption

when a wave strikes an object and goes into it

interference

when two or more waves combine to form a new wave

draw a transverse wave and label crest, trough, wavelength, and amplitude

draw a longitudinal wave and label a compression, rarefaction, and wavelength

define amplitude and how it looks different on a transverse and a longitudinal wave

it’s the amount of energy carried by a wave; in transverse waves it is the height of the wave and in longitudinal waves it’s the amount of compression in the wave

explain the Law of Reflection. include a picture of it with the incident ray, reflected ray, angle of incidence, and of reflection, and normal labeled

angle of incidence = angle of reflection

it is the angle of incidence is always equal to the angle of reflection

draw a picture to show the difference between constructive and destructive interference

ex. a wave has a frequency of 3.2 Hz with a wavelength of 10m. what is the velocity of the wave?

32 m/s

matter

anything that takes up space and has mass

substance

all particles in matter are identical (fixed composition)

mixture

two or more substances physically combined (variable composition)

element

simplest form of matter from which more complex substances are made

compound

two or more elements chemically combine in a fixed proportion

differentiate between a homogeneous mixture and a heterogeneous mixture

a homogeneous mixture is when components are evenly distributed out on a microscopic level; while a heterogeneous mixture is when the substances in the mixture are not evenly spread out

density

measure of compactness or consistency of a material

what is the formula for density

density = mass/volume

combustibility

how easily a substance will set on fire ex. burning charcoal

reactivity

how easily a substance reacts, usually with an acid or base

oxidation

how easily a substance reacts with oxygen

chemical reaction

process by which the atoms of one or more substances are rearranged to form different substances

law of conservation of matter

matter is neither created nor destroyed during a chemical change, it only changes forms

explain the difference between solids, liquids, and gases. include volume, shape, and particle motion in your description

a solid has a fixed volume, a fixed shape, and particles are help tightly together with low KE; a liquid has a fixed volume, shape changes based on container it is in, and particles have more KE than solids; a gas has no fixed volume or shape, particles will spread out to fill the container (called diffusion), and the particles have high KE

sketch a sample heating curve of water and label melting point, boiling point, heat of fusion, heat of vaporization, solid, liquid, and gas

atom

the smallest particle of an element that still has the properties of that element

proton

positive particle on the nucleus

neutron

neutral particle in the nucleus with protons

electron

negative particle outside of the nucleus in the electron cloud

quarks

what protons and neutrons are made of; the smallest known particles

valence electrons

the electrons in the atom’s outermost energy level in the electron cloud

atomic number

tells the number of protons in an atom of the element; used to identify an element

mass number

not on the periodic table; tells the number of protons and neutrons in the nucleus of an atom

isotopes

atoms of the same element with different numbers of neutrons

average atomic mass

weighted average of all of the different versions of an element (called isotopes)

explain what two isotopes of the same element have in common and what is different between about them. include when an isotope is considered to be most stable

they have the same numbers of protons, which defines the element, but they are different because of the number of neutrons which leads to different mass numbers; and isotope is most stable when it has balanced amount of both protons and neutrons

differentiate between the characteristics of metals, nonmetals, and metalloids. include their general location on the periodic table

metals are shiny silvery solids, goof conductors of heat and electricity, malleable and ductile, located on the left of the metalloids; nonmetals are gases or dull brittle solids, poor conductors, right of the metalloids; metalloids are solids, semi-conductors, physical properties like metals, chemical properties like non-metals

use the periodic table to determine the identity of each group described below ex. their atoms have 5 valence electrons, they are the most reactive metals, they do not react in nature

nitrogen group, alkali group, and noble gases group

use the periodic table to determine the identity of each element described below ex. the first element in group 13, a period 2 nonmetal with 6 valence electrons, a metalloid with 71 neutrons, a gas with 2 valence electrons and 1 energy level in its electron cloud

boron. oxygen, antimony, helium

chemical reaction

process by which the atoms of one of more substances are rearranged to form different substances

reactants

starting substances; “ingredients”

products

ending substances; what is made

aqueous

dissolved in water

explain the law of conservation of mass and how it relates to the amount of reactants and products

it states that matter can neither be created nor destroyed, it can only change forms; therefore, the mass of the reactants must equal the mass of the products

balance this equation: AlBr₃  +  K₂SO₄  →  KBr +  Al₂(SO₄)₃

2 AlBr₃ + 3 K₂SO₄ → 6 KBr + Al₂(SO₄)₃

balance this equation: Al  +  O₂  → Al₂O₃

4 Al + 3 O₂ → 2 Al₂O₃

balance this equation: . LiCl  +  Br₂ →  LiBr  +  Cl₂

2 LiCl + Br₂ → 2 LiBr + Cl₂

balance this equation: NF₃  →  N₂  +  F₂

2 NF₃ → N₂ + 3 F₂

balance this equation: C₄H₁₀  +  O₂  →  CO₂  +  H₂O

2 C₄H₁₀ + 13 O₂ → 8 CO₂ + 10 H₂O

balance this equation: Pb(OH)₂  +  HCl  →  H₂O  +  PbCl₂

Pb(OH)₂ + 2 HCl → 2 H₂O + PbCl₂

synthesis

2 or more reactants combine to make 1 product

decomposition

when 1 reactant breaks down into 2 or more

combustion

when something is burned

single replacement

one element replaces a similar element in a compound

double replacement

two ionic compound reactants switch ions forming two new ionic compound products; usually results in the formation of a precipitate (an insoluble compound that comes out of the solution)