ICP Final

chemistry

study of matter and energy

steps of the scientific method

1. Define the problem
2. Gather information
3. make a hypothesis
4. perform the experiment
5. analyze the data
6. conclusion

independent variable

what you are testing; the thing being manipulated

dependent variable

what is being measured (changed by the independent)

control

the thing that stays the same

standard

a quality that people agree to use for comparison

scientific law

description of events in nature; WHAT happens

scientific theory

explanation of events in nature; WHY things happen

scientific model

representation of an object or event that can be used to understand the real thing (which may be too complex, small, or large to see)

science

observing, studying, or experimenting to find patterns in nature

technology

application of science usually resulting in an invention

Giga(G)

1 billion

Mega(M)

1 million

Kilo(k)

1000

Deci(d)

1/10

Centi(c)

1/100

Milli(m)

1/1000

Micro(µ)

1/1,000,000

Nano(n)

1/1,000,000,000

length

distance from one point to another (meter)

mass

the amount of matter in an object (gram)

volume(V)

the amount of space and object takes up (liter)

density(D)

the amount of matter in a given amount of space (mass/volume)

scientific notation

write a very large or small number as a power of ten (Ex: 750,000,000 = 7.5*10^8)

which variable goes on the x-axis?

independent variable

which variable goes on the y-axis?

dependent variable

accuracy

How close your measurement is to the real one (correct)

precision

how close your measurement is to other measurements made in the same way (repeatable)

how do you add and subtract to correct sig figs? (1.2+2.53)

round answer to the left-most estimated digit (3.7)

how do you multiply and divide to correct sig figs? (125/5)

round answer to the least number of sig figs (30)

matter

anything that has mass and takes up space

pure substances

matter with a definite composition and definite properties

element

simplest form of matter

atom

the smallest particle of an element that still acts like that element

chemical symbol

shorthand way of writing the names of the elements

compound

2 or more elements that are chemically combined

molecule

the smallest particle of a substance that still acts like that substance

chemical formula

shorthand way of writing out compounds

mixtures

2 or more kinds of matter (pure substances) PHYSICALLY mixed together
-can be separated using physical properties
-no fixed ratio
-similar properties as substances in the mixture

homogeneous mixture

substances are spread out evenly (Ex: salt water, air)

heterogeneous mixture

substances are NOT spread out evenly (Ex: chocolate chip cookie, pizza, sand)

alloys

homogeneous mixtures of metals (Ex: bronze)

colloids

looks like particles are spread out evenly but aren't (Ex: butter, pearls)

suspension

particles that settle to the bottom (Ex: Italian dressing, hot chocolate)

physical properties

properties that can be observed with 5 senses and measured (Ex: color)

chemical properties

ability to react or the lack of ability (Ex: flammability)

intensive properties

does NOT depend on the amount (Ex: color, density)

extensive properties

depend on the amount (Ex: mass, volume)

physical change

-only a change in physical properties
-usually reversible
-Ex: melting, freezing

chemical change

a process by which new substances are formed having new physical and chemical properties; not easily reversible (Ex: rusting, burning)

4 signs of a chemical change

1. bubbles (gas is forming)
2. heat or light (burning)
3. color change
4. precipitate (2 liquids become solid)

steps for proving a calculation

1. write down the information given to you
2. write down the equation you are going to use
-use variables and move for the solved variable
3. substitute letters for units
4. answer

melting point

temperature that a solid turns into a liquid

boiling point

temperature that a liquid turns into a gas

synthetic

man-made

solid

substance with definite shape and definite volume

liquid

substance with definite volume but no definite shape

gas

substance with no definite shape or volume; fills its container

plasma

similar to a gas but with charged particles (most common phase in the universe)

kinetic theory of matter

-all matter is made up of tiny particles in constant motion
-the higher the temperature the faster the particles move
-particles with less mass move faster

thermal energy

higher temp. → particles move faster → more energy

movement in solids

particles are close together and vibrate in place

crystalline solid

particles are in a pattern (most common solid)

amorphous solid

particles are not in a pattern

movement in liquids

particles are close together but can slip past each other (flow)

viscosity

resistance to flow (high: molasses, glue ~ low: water, juice)

movement gas

particles move in a straights line until they collide with something and change directions

melting

solid → liquid

freezing

liquid → solid

vaporization

liquid → gas

condensation

gas → liquid

deposition

gas → solid

sublimination

solid → gas

endothermic phase change

requires energy to be added
-melting
-boiling
-evaporation
-sublimation

exothermic phase change

releases energy
-freezing
-condensation
-deposition

boiling vs evaporation

Archimedes Principle

the buoyant force on an object is equal to the weight of the fluid displaced by the object (duck)

Bernoulli's Principle

the pressure in a moving stream of fluid is less than the pressure in the surrounding fluid (hair dryer + ping pong ball)

Pascal's Principle

the pressure in a fluid is transmitted equally throughout the fluid (hydraulics)

pressure equation

F1/A1 = F2/A2

Boyle's Law

P1V1 = P2V2

Charles' Law

V1/T1 = V2/T2

Gay-Lussac's Law

P1/T1 = P2/T2

Heisenberg's Uncertainty Principle

the location of an electron can only be described in terms of probabilities of where it might be located

protons(p+)

positive electrical charge
1 atomic mass unit(amu)

neutrons(n)

no electrical charge; neutral
1 amu (slightly larger than p+)

electrons(e-)

negative electrical charge
1/1836 amu

Atoms are...

neutral; p+ = e-

Main energy levels

1,2,3,4,5,6,7

sublevels

s,p,d,f

s

1 orientation (max 2 e-)

p

3 orientations (max 6 e-)

d

5 orientations (max 10 e-)

f

7 orientations (max 14 e-)

orbitals

s p d f

1 1s

2 2s 2p

3 3s 3p 3d

4 4s 4p 4d 4f

5 5s 5p 5d 5f

6 6s 6p 6d 6f

7 7s 7p 7d 7f

Al

Aluminum

C

Carbon

Cl

Chlorine

H

Hydrogen

Mg

Magnesium