Matter, Mass, Volume
mat - anything with mass & volume |
mas - quantity of substance contained, usually measured in grams or kilograms |
v - amount of space occupied, usually measured in millilitres, litres, or cubic centermetres |
Density
ratio of mass to volume, m/v |
State of Matter & Fluid
solid - fixed mass, volume, and shape |
liquid/fluid - fixed mass and volume |
gas/fluid - fixed mass and container has fixed volume |
fluid - matter that can flow (ex: liquid, gas), no fixed shapes, takes on the shape of the container |
Physical Property
p - type of characteristics that can be observed or measured w/out changing its identity of |
Qualtitative
not measurable |
malleable - able to be flattened into sheets |
ductile - able to be stretched into wires |
crystalline structure - shape of appearance of crystals |
Quantitative
measurable |
solubility - ability to dissolve in water |
conductivity - ability to conduct electricity tor heat |
density - ratio of mass to volume |
viscosity - resistance to flow |
Chemical Property
ability to react chemically with other substances to form new substances |
can only establish when composition of matter is altered (ex: reactivity) |
Pure substances
homogenous - uniform apperance |
has a unique set of properties |
cannot turn into simpler substances by physical means |
can be further classified as element or compound |
Elements & Compounds
e - simplest pure substance, cannot be broken down or separated into simpler substances |
reason - it's already simple since each elements is made of 1 kind of atom |
have different names in different languages |
chemical symbols consist of 1 or 2 letters, 1st is capitalized |
c - composed of 2 or more elements in a specific way, can be changed into simpler substances by chemical means |
Mixture
made of 2 or more substances, physically put together |
can be separated into simpler substances by physical means |
|
|
Metals
properties - hard, shiny, malleable, ductile, good conductors of heat and electricity |
left of the staircase of Periodic Table |
Non-Metals
properties - gas or brittle solid at room temperature, not malleable or ductile, dull, poor conductors of heat and electricity |
right of the staircase |
Metalloids
elements that shares some properties of metals and non-metals |
properties - brittle solid, can be dull or shiny, may conduct electricity, poor conductor of heat |
Hydrogen & Oxygen
H - makes up 90% of the atoms in the universe |
O - produced by plants as a by-product of photosynthesis, combined w/ sugar in our cells to release energy |
Iron, Silver, Mercury, Mercury Vapour
Fe - an important material in structures, mixed w/ carbon makes steel, can rust when exposed to water & oxygen |
Ag - better than other metal at conducting heat & electricity and reflecting light |
Hg - a poisonous metal as liquid at room temperature |
Chlorine, Silicon, Semiconductor
Cl - forms table salt when combined w/ sodium |
Si - 2nd most common element, after oxygen in earth's crust, widely used as a semiconductor in manufacturing computer chips and hardware |
s - a poor conductor of electricity at low temperature but a good c at high temperature |
Physical Change
occurs when no new substances form, but there may be a change in appearance |
Chemical Change & Precipitate
occurs when substances combine (react) to form new substances |
evidence: colour change, heat, light, or sound produced, bubbles of gas, precipitate |
p - solid produced in mixing 2 solutions |
Reactants & Products
r - substances that are going to react |
p - new substances that are produced |
Chemistry
study of matter and its change |
includes: facts & observations about matter, summarize patterns of behaviour in matter, theories that explain the patterns of behaviour in matter |
Models
help to visualize objects or processes that cannot be seen directly |
Theory
provides a scientific explanation based on the results of experimentation |
Particle Model of Matter
all matter is made of small particles that are too small to be seen with eye and even a microscope |
there are spaces between the particles, the amount of spaces varies w/ the state of matter (greatest in gas, least in solid) |
the particles are always moving, collides w/ each other & the container in liquid & gas |
particles are attracted to one another, strength depends on the type of particles |
|
|
Thermal Energy, Heat, Collision, Temperature
te - the total kinetic energy of all the particles in a substance |
h - thermal energy that is transferred from 1 body to another |
c - particles transferring kinetic energy |
t - the average kinetic energy of the particle in a substance |
particles in hot objects have more kinetic energy and move faster |
Kinetic Molecular Theory
explains how changes in the kinetic energy of the particles can result in changes in state |
energy makes particles move, more energy the particles have from heating, the faster they move and farther apart they get |
Thermal Expansion, Thermal Contraction
increase in volume of a substance when its temperature is raised |
the decreased in volume of a substance when its temperature is lowered |
Change of State by Heating
particles in solids are tightly packed together = cannot move freely (fixed in position), holds a definite shape, can and do vibrate constantly |
as heat is added, kinetic energy of the par increase and begin to collide w/ each other = more spaces is created between the particles |
if enough heat is aded, the solid will melt |
par in liquid are close (in contact w/each other) but have enough space to slide past, don not hold a shape instead take on the shape of its container |
as heat is added to a liquid, kinetic energy of pars increase, collide more = more space created |
some par gain enough energy to break free, w/ enough heat , the liquid will boil |
pars in gas are highly energetic, can move freely and quickly in all directions, spread out to fill their container, gas is mostly empty space as pars are far apart |
Temperature which Change of State Occurs
melting point - temperature where solid melts o liquid (ex: 0 celcius for water) |
boiling point - temperature where liquid boils to gas (100 celcius for water), substances condense at the same temp at which they boil |
freezing point - temperature where liquid freezes to solid, same temperature as melting point, substances freeze at the same temp at which they melt |
Chemical Bonds (Chemical & Physical)
c - new substances are produced in the process of breaking existing chemical bonds and forming new bonds |
chemical bonds - forces that hold 2 or more atoms together |
a change in composition occurs, changes are difficult to reverse |
p - bonds hold atoms together (in molecules and ions), do not change, easier to reverse |
Energy Change, Exothermic, Endothermic
ec - energy is either released to the environment or absorbed from the environment due to energy change in matter chemical change |
energy change in a chemical change might or might not be noticeable |
ex - release of energy in the form of heat and light |
en - absorption of energy |
Corrosion (Chemical Change)
the process where metals are broken down |
rusting - corrosion of iron, rust is produced in a chemical reaction between iron and water containing dissolved oxygen gas = structural failure |
|
