science

Matter

all physical things that take up space and have mass

states of matter include liquid, gas, and solid

subatomic particles

particles that’s smaller than atom, it’s the building block of atom including electrons, protons, and neutrons

atomic number

the amount of protons (also equals to the number of electrons because they are the same)

atomic mass

proton plus neutrons ( they all have one mass)

Isotopes

atom with the same amount of protons but different amount of neutrons

shells/ layers

fixed energy level around the nucleus

valence

the outermost electrons

chemical bonds

a strong force that hold atoms or ions together:

ionic bond, covalent bond, metallic bond

ionic bond (metal with non metal )

attraction between oppositely charged atoms

ions

charged atoms

anion

negative ion

cation

positive ion

polyatomic ions

group of two or more atoms chemically bonded together, with an overall positive or negative electrical charge.

covalent bond (non metal with non metal)

atoms sharing one or more pairs of electrons to form a molecule

molecular compound

a compound made up of neutral molecules, formed by covalent bonds between different non‑metal atoms.

polar bonds

electrons shard unequally between two non metal atom like H2O

non-polar bond

electrons equally shared, this happens most commonly between two atoms of the same element. like F2

metallic bond

the bond between metal cations and the surrounding sea of free negative electrons.

element groups/ family

vertical column of the periodic table, same group have the same number of valence electrons

Alkali metals

group 1

Alkaline earth metals

group 2

Halogens

group 17

Noble gases

group 18

transition metals

group 3 to 12

period

the horizontal role in the periodic table, same period share the same amount of shell/s. there are 7 group in total. e.g. group 1 has one shell

chemical reaction

one or more substance are changed into new substance while the total mass of substance remains the same

physical state (state symbol/ common symbols)

(s) solid, (g) gas, (l) liquid, (aq) aqueous dissolve in water

synthesis

two or more simple element/ substance combine to form a more complex compound/ product (A+B-AB)

decomposition

one single compound being broken down into two or more simpler substances

combustion

a substance react rapidly with oxygen to generate heat and light

displacement reaction

when a more reactive element replace a less reactive element in a compound

single replacement

One free element can replace or substitute another element within a compound.

double replacement

two ionic compound swap their positive and negative ions to create two new compounds

Neutralization

a type of double replacement when acid and bases react to form water/salt

homogeneous mixture (solution/ uniform)

a mixture where substances are mixed completely, particles is tiny and distributed evenly. It’s usually transparent that allows light pass through

solute

substance that’s dissolving

solvent

substance solute dissolve in

heterogeneous mixture

A heterogeneous mixture is a mixture whose composition is NOT uniform/ do not dissolve. the substance suspended then settled/ deposit. cannot transmit light well

emulsion

a mixture of immiscible liquids (liquid that do not mix together) with one in form of small droplet in another. It is a stable suspension

Suspension

a heterogeneous mixture, where solid particles are suspended inside liquid (or gas).

colloid

intermediate between a homogeneous mixture and a heterogeneous mixture

Tyndall effect

The Tyndall effect is the scattering of light by small dispersed particles inside a mixture.

Brownian motion

the random movement of suspended particles in a fluid. It is caused by collisions with constantly moving molecules and provides evidence for the kinetic theory of matter.

Solubility

the maximum amount of solute that can dissolve in a given quantity of solvent at a specific temperature to form a saturated solution.

Saturated solution

a solution that contains the maximum amount of a solute that can be dissolved at a given temperature.

unsaturated solution

below the solubility maximum at a given temperature; more solute can still dissolve.

supersaturated solution

A supersaturated solution contains more dissolved solute than a saturated solution at the same temperature. above the solubility limit.

insoluble 不可溶解的

cannot dissolve in a solvent

soluble

can dissolve in solvent

immiscible

liquid insoluble in another liquid

miscible

two liquid mix completely together to form a single homogeneous liquid; they will NOT separate into two layers.

completely miscible

Two liquids can mix in any proportion to make one single homogeneous solution.