Chemistry 9 weeks

Page 1

9 weeks study guide chemistry II

Ch 1,2, 4,5, 6,

Ch 1

Chemistry is the central science.

Matter- anything w mass and takes up space

Mass- how much matter is in an object

Weight- calculation of mass and the force of gravity on it

Organic chem- usually contains carbon

Pharmaceuticals, plastics

Inorganic- usually doesn’t have carbon

Minerals, metals, nonmetals, semiconductors

Physical- behavior and changes of matter and the related energy changes

Reaction rate’s reaction mechanisms

Analytical- components and composition of substances

Food nutrients, quality control

Biochemistry- matter and processes of living organisms

Metabolism, fermentation

Ozone layer- O3 > protects from UV rays.

CFCs- dangerous, used for coolants, Midgley Jr. was first to invent them in 1928. They are nontoxic and stable, but they bond with O3 and they hurt the atmosphere.

High energy radiation that has no charge and no mass- Gamma rays (just neutrons)

Weighted average mass of an element’s isotopes- atomic mass

Systemic approach used in all scientific study- scientific method

Qualitative data- information that describes color, shape, or some physical characteristics (cannot be in numbers)

Quantitative data- countable, numerical

(Know how to identify each)

Chemical that protects from UV rays- O3

Visual, verbal or mathematically explanation of how things occur- model.

The study of matter and the changes it undergoes- chemistry

The act of gathering information- observation

Tentative explanation of what has been observed- Hypothesis

Set of controlled observations that tests a hypothesis- Experiment

Hypothesis supported by many experiments- theory

Summary of accepted facts of nature- natural law

Independent variable- changed on purpose

Dependent variable- changes as a result of independent variable

Control- standard of comparison

Applied research- for a purpose

Pure research - for the sake of knowledge

Be able to identify examples

Why is UV not matter? Doesn’t have mass/ take up space

A conclusion is based on? The data obtained

How do you prepare an acid solution? Add the acid slowly to water bc the acid reacts violently w water.

All that we observe about matter depends on atoms and the changes they undergo

Chemistry seeks to explain the submicroscopic events that lead to macroscopic events

False- Very little of matter and its behavior is macroscopic- everything on the big scale is due to tons of lil things on the little scale

Control is a standard to compare

You cannot tell if glass is hot based on visuals

mass is obtained by placing the chemical on the pan of balance- no, in container on piece of paper or just on paper

goggles are always necessary in lab

steps of scientific method-

observation, hypothesis, experiment, analysis, conclusion

constants cannot change

a model is supported by many experiments

Molina and Rowland figured out the tea on CFCs

Chlorine forms from the CFCs breaking up the ozone (more CO2)

Chapter 2

Si measurement units allow scientists to report data that can be reproduced by others.

Adding prefixes to SI units extends their ranges

SI base units include the meter for length, second for time, kilogram for mass, kelvin for temp.

Meter- distance light travels in a vacuum in 1/299792458 s

Second- microwave frequency given off by a Ce-133 atom

Kilogram- platinum-iridium cylinder that is stored at a constant temperature and humtity.

Cubic meter- cube whose sides all measure exactly one meter

Any substance with a definite composition- chemical

Unit in a system of measure that is defined by combining base units- derived unit

Examples- volume (m3) and density (g/cm3) – d= m/v

defined unit in a system of measurement that is based on an object or event in the physical world- Base unit

Visual representation of data- Graph

Circle graphs show parts of a whole, bar graphs show how a factor varies w time, location or the like.

Relationship between independent and dependent can be linear or nonlinear

Data on a graph is considered continuous, thus, you can interpolate or extrapolate data from a line graph.

Scientific notation- mean of expressing numbers as multiple of 2 factors a number between 1-10 and ten raised to a power

Rules for scientific notation-

1. add/sub must be in the same power

2. add or sub the exponents for multiply and divide

Dimensional analysis- uses conversions that are equal to one to change units

Significate figures- all known digits plus one.

There are rules for sig figs on page 39

If an answer has 4 significant figures, 3 are known and 1 is estimated

Precision- how close multiple measurements are to each other

Accuracy- how close to the accepted value the measurements are

Key equations-

Density= m/v

Conversion between C and K > C+273=K and K-273=C

Percent error = error/ accepted value x 100

Slope of a graph = Y2-Y1/X2-X1

Chapter 4

Early theories of matter- Democritus- proposed idea of atoms. Dalton in 1808- propsed atomic theory (his).

Dalton was a lil wrong

All matter is composed of atoms. An atom is the smallest particle of an element that maintains its characteristics.

Atoms with the same number protons but different neutrons- isotope

Isotope information-

gamma rays- high energy radiation that has no charge and no mass

Center of an atom, contains neutrons and protons- nucleus

Equal to ½ mass of a carbon-12 atom- atomic mass unit

Process not requiring energy by which unstable nuclei lose energy- radioactive decay

States that all matter is composed of atoms- Daltons atomic theory

Process by which some substances spontaneously emit radiation- radioactivity

An atoms nucleus contains its protons and neutrons

Neutrons have no electrical charge

Alpha particles have a charge of 2+

An alpha particle has 2 protons and 2 neutrons

Protons have a mass Electrons x 1840

Atoms have no charge bc same number of protons and neutrons. Ions have charges.

Ratio of proton to neutron gives the stability to an atom: if it’s not equal its unstable; unstable nuclei go into radioactive decay emitting radiation in the process

Atomic number = protons = electrons

Number of neutrons = Mass number – atomic number

Chapter 5

Ground state- lowest allowable energy state of an atom

Orbital- a 3-dimensional region around the nucleus

Aufbau’s principle-states that each electron occupies the lowest energy orbital available

Hund’s rule- states that single electrons with the same spin must occupy each equal energy orbital before additional electrons with oppo spins can occupy the same orbital.

Pauli’s exclusion principle- states that a maximum of two electrons may occupy a single atomic orbital, but only if the electrons have opposite spins.

Electron configuration- a shorthand method for describing the arrangement of electrons in an element’s atoms.

Valence electrons- electrons in the outermost shell

Electron dot configuration- consists of an element’s symbol w the valence electrons around it

Electromagnetic radiation- a form of energy that exhibits wavelike behavior as it travels through space.

Electromagnetic spectrum- encompasses all forms of electromagnetic radiation w/ the only difference between the types being the frequency and wavelength

All waves can be described by their wavelength, frequency, amplitude, and speed

Wavelength- the shortest distance between equal points on a continuous wave

Frequency- number of waves that pass a given point per second

Amplitude- waves height from origin to crest

Quantum- minimum amount of energy that can be gained or lost by an atom

Planck’s constant- 6.626 x 10-34 j x s

Atomic emission spectrum- set of frequencies of the electromagnetic waves emitted by atoms of the element

Heisenberg uncertainty principle- impossible to know exact location and velocity of a particle at the same time

De Broglie equation- predicts that all moving particles have wavelike characteristics

Quantum mechanical model of the atom- an atomic model where electrons are treated as waves

Atomic orbital- probable location of electrons

Principal energy levels, sublevels,