Chem study guide for Final

First Greek Philosopher

First Greek Philosopher

Democritus 400 B.C

Theory: World made of empty space and tiny particles called atoms (Discovered atoms)

Aristotle

Contracted Daltons Theory (No such things as smaller particles)

John Dalton (1808)

Created a logical hypothesis (First person to prove the existence of an atom)
Theory: Matter can not be created nor destroyed

Daltons conclusion/theory

1.) All mater composed of small, indivisible particles called atoms.

2.) All atoms of an element were exactly alike in mass, atoms of different elements were unlike in mass

3.) Law of Definite Proportions: Atoms always combine in simple ratios to form the same compound

4.) Chemical reactions happen when atoms separate, join, or rearrange. Elements will never become another element

Thompson

“All elements have negatively charged particles.”

(Plum pudding idea)

Steps:

1.) Applied high voltage in a cathode ray tube to create cathode rays

2.) Rays bent in a magnetic field indicating they were negatively charged

3.) Led to the discovery of electrons

Milikan: (Thompsons Student)

Steps:

1.) Measured tiny charged oil droplets

2.) Balancing gravitational and electric forces on droplets in an electric field.

3.) measuring the charge on the droplets he determined the charge of the electron

Conclusion: Charge of the electron

Rutherford

Steps:

1.) firing alpha particles at a thin sheet of gold

2.) particles passed through but some deflected and showed dense nucleus

(Conclusion that atoms have a central nucleus.)

Subatomic Particles

Proton- In the nucleus, (+), 1 amu
Neutron- In the nucleus, (None), 1 amu
Electron-Outside nucleus, (-), 0 amus

Isotope format:

Mass on top

Atomic number on bottom

Subtract to find Neutron

Elements

Alkali Metals

First Column

Alkali Earth Metals

Second Column

Metalloids

Staircase

Noble Gasses

Last Column

Lanthanoids

Bottom first row

Acintides

Bottom second row

Halogens

Second to last column

Metals

Everything else

Atomic Radium

Top to Bottom- Increases in size

Left to Right - Decreases in size

Electronegativity

Top to bottom- More attractive to less attractive

Left to right- Less attractive to more attractive

(Do not include noble gasses)

(Bigger the radius MEANING LESS ATTRACTIVE)

Ionization

Left to right - easier to steal to harder to steal

Top to bottom- harder to steal to easier to steal

(Bigger the radius the easier to steal)

Electron Configuration

Aufbau Principle

Lower energy levels first

(When it goes out of order you know it is wrong)

Pauli Exclusion

Opposite spins when together
(Can only have max of arrows)
s=2, p=6, d=10 f=14 anything more breaks this rule

Hunds Rule

Take available orbitals first
(All arrows must point one direction before going the other)

What is Chemistry

Chemistry is the study of matter and the
changes that it undergoes.

The SI base unit for Time

Second

The SI base unit for Length

Meter

The SI base unit for Mass

Kilogram

The SI base unit for Temperature

Kelvin

Pure Research

A type of scientific investigation that seeks to gain knowledge for the sake of knowledge itself

Applied research

A type of scientific investigation that is undertaken to solve a specific problem

Model

A visual, verbal, and or mathematical explanation of data collected from many experiments

Derived unit

A unit defined by a combination of base units

Liter

The metric unit for volume equal to one cubic decimeter

Density

The amount of mass per unit volume

Graph

A visual display of data

Significant figures

The number of all known digits reported in the measurements plus one estimated digit

Example of Scientific Notation
702.0 g

7.020 × 10² g
(Making 702 smaller to 7.02 by moving 2 spaces left meaning it is power ².)

Example of Scientific Notation
00000702 g

7.02×10^-6g
(Making 00000702 by making it bigger to 7.02 by moving 6 spaces right meaning it is power ^-6

When a small amount of sugar is dissolved in water it is a

Homogenus solution (Uniform)

Water being mixed with oil

Heterogenus solution

A change between the three states of matter (Gas, Liquid, Solid)

Physical change

Hypothesis

An explanation from observations that is tested /testable

(Example: If I drop a ball it will fall to the ground)

Theory

A well established explanation that is supported by a body of evidence

Example: Evolution

Types of Chemistry:

Prefixes

Adding & Subtracting with Significant Figures

Multiplying and Dividing with Significant Figures

Chemical Property

A chemical property relates to a substance’s ability
to undergo changes that transform it into different
substances
• A change in which one or more substances are
converted into different substances is called a
chemical change or chemical reaction.

Physical Property vs Physical Change

A physical property is a characteristic that can be
observed or measured without changing the identity
of the substance.
• melting point and boiling point

A physical change is a change in a substance that
does not involve a change in the identity of the
substance.
• grinding, cutting, melting, and boiling point

Intensive properties

do not depend on the amount
of matter present.
• melting point
• boiling point
• density
• ability to conduct electricity
• ability to transfer energy as heat

Plasma

Plasma is a high-temperature physical state of matter
in which atoms lose most of their electrons, particles
that make up atoms.

Different Mixtures

A mixture is a blend of two or more kinds of matter, each of which retains its own identity and properties.
• mixed together physically
• can usually be separated

Homogeneous mixtures are called solutions
• uniform in composition (salt-water solution)

Heterogeneous mixtures
• not uniform throughout (clay-water mixture)

Pure Substance

A pure substance has a fixed composition.
• Pure substances are either compounds or elements.
• A pure substance differs from a mixture in the
following ways:
• Every sample of a given pure substance has exactly the same characteristic properties

Dimensional Analysis

Tutorial

Density

Mass / Volume

Mass

Density x Volume

Volume

mass / density

How to write Mass, Volume , Density

Mass usually written as g or cm³

Density usually written as g/ml or cm³/mL

Volume usually written as mL

How to calculate Percent Error

|error| / accepted value x 100

Accuracy

Refers to how close a measured value is to an accepted value

Precision

Refers to how close a sense of measurements to another

Conversions:
(DO NOT STUDY ALL ONLY WHAT SHE GAVE)

K- Kilo (3)

H- Hecta (2)

D- Deca (1)

b- base; gram meter liter (0)

D- Deci (-1)
C- Centi (-2)

M- Mili (-3)