Class notes Science (essentially for studying)

Science study Notes
〜Changes in matter〜


3 types of changes:


⟶ physical change
⟶ chemical change
⟶ nuclear transformations


Physical change: molecules dont change. New substance is not formed.
Chemical change: molecules change. New substance is formed

Physical change Chemical change

Size/shape change Altered molecules

Phase (liquid, solid) Gas formed
change

Density change Aroma, colour change

Texture change Precipitate formed

Color change Energy released or
absorbed


Chemical equations: chemical changes or chemical reactions, can be represented with chemical
equations.


Reactants + Products
↓ ↓
2Ag + H2S ⟶ Ag2S + H2


*always put the phase for each element*


S- solid
L- liquid
G- gas
Aq- aqueous

, Law of conservation of Mass


⟶ In a chem rxn matter is neither created nor destroyed.
⟶ The number and type of atoms going into a rxn must be the same as the number and type of
atoms released.
⟶ If an equation obeys the law of conservation, it is balanced.


Diatomic molecules


I Have No Bright Or Clever Friends


I2, H2, N2, Br2, O2, Cl2, F2


Nomenclature review:


Is there a metal?
↓ ↓
Yes No
↓ ↓
Ionic bond covalent bond


Ionic bond:


⟶ N.metal + metal
⟶ Name first element+name metal first
⟶ If you have a polyatomic ion, name it otherwise name the second element -ide


Covalent bond:


⟶ n.metal + n.metal
⟶ name first element + prefix
⟶ name 2nd + prefix -ide