Criterion A Chemistry Assessment Revision

endothermic

heat enters system

exothermic

heat leaves the system

conduction

heat travels from one particle to another particle in solids. As particles heat up, they move faster and bump together.

insulators

materials that don't allow heat energy pass through them.

convection

heat travels in liquids and gases

radiation

heat travels in rays in straight lines, makes heat shadows just like light.

matter

any thing that has mass and takes up space

physical properties

density, melting point, malleability (bendable - copper)

chemical properties

reactivity, flammability, acidity

Elements

purest form of matter, cannot be broken down

any amount of pure element has unique physical and chemical properties of that element

atom

smallest part of an element that still has properties of an element

HOMOGENOUS mixtures

the components that makes the mixtures uniformly distributed throughout the mixtures

HETEROGENOUS mixtures

the components of a mixture that aren't uniformly distributed and can be seen clearly

COMPOUNDS

pure substances that are made of 2+ elements chemically bonded together. Has different properties that individual elements have.

MIXTURES

combo of different elements and compounds (PHYSICAL)

Solution

mixture of 2+ types of matter evenly spreaded and not easily seperated forms when one solution dissolves in another

suspensions

particles are large so they settle out of the solvent if not constantly stirred

colloids

particles are medium between suspensions and solutions

hydrophilic

water liking

hydrophobic

water repelling

SIEVE/MESH SCREEN

small matter will pass through, large matter will stay behind (s > s)

DECANTING

gradually pour liquid from a container to another to separate sediments (l > s)

FILTRATION

only small particles can pass through pores, separates solids from liquids

EVAPORATION

liquid is boiled away, when water is boiled away, solid remains

groups

columns

periods

rows

blue

metal

non blue

non metal

electrons

-

protons

+

neutrons

neutral

boiling point

100

body temp

37

room temp

20

c to k

273

Unexpected colour changes:

shrimp cooked

fireworks

leaves changing

Unexpected temperature changes:

warm/cold packs

baking soda + vinegar = temp drops

body temp rises to kill infections

COMBUSTION - burning - exothermic

wood burning

candle

rusting

BUBBLES

bubble boms

baking soda + vinegar

tablets

Physical change

changes apperance of substance, does not turn substances into something new

irl examples of physical

whipping eggs

boiling water

dissolving sugars

dicing veggies

properties of physical

changes state of matter, texture, shape, temperature and colour

Chemical change

2 or more substances join to form something new with new chemical properties

irl examples of chemical

iron rusting

gas burning

bread rising

cooking eggs

properties of chemical

2+ substances interact to create something new, bonds of two atoms break and form new molecules

chemical FORMULA - Combustion of methane

CH₄ + 2 O₂ → CO₂ + 2 H₂O

word FORMULA - Combustion of methane

Methane + oxygen → carbon dioxide + 2 water

DIATOMIC (two atoms)

in its pure form is always bonded to itself, twins

7 diatomic elements

"I (Iodine, I2) H (Hyrdogen, H2) ave N (Nitrogen, N2) o B (Bromine, Br2) right O (Oxygen, O2) r C (Chlorine, Cl2) lever F (Florine, F2) riends"