Chem 141 chapter 1

A law

tells you what

A theory

tells you why

Sizing from largest to smallest

Cells.Molecule.atom

Graphite AFM

A way to see atoms

Atoms originally were found by

The greeks.. It was based on philosophy

Brownian motion

Random motion of atoms and particles

What did the greeks believe that was incorrect

They believed that shape determines properties

Molecular level structure determines…

Properties

Greeks were right about

atoms in constant random motion

Atoms characteristics

Neutral. 2 protons 2 e-

compound

2 or more different atoms (EX: 2 He atoms and 1 H atom)

Daltons atomic theory

Elements are composed of small, indivisible particles called atoms. all atoms of an element are the same

whos model is this

daltons model

what are in the nucleus

Protons and neutrons

JJ thompson discovered

the e-

how did jj thompson discover the e-

By using the cathode ray tube, when he shot particles toward the + and - anodes, the particles bent towards the + anode, showing that there is a - particle in an atom

whos model is this

Thompsons model

Ernest rutherfords experiment

Gold foil experiment. evidence that the nucleus exists

alpha particle

2 protons, 2 neutrons, positively charged

rutherford experiment shows

atoms are mostly empty space and theres small, dense, nucleus in atoms center

whos model is this

Rutherfords planetary model

Neutrons were the ____ atoms to be found

last

why were neutrons the last to be discovered?

because they have no charge and cant be manipulated with magnetic fields

coulombs law

opposite charges attract, like charges repel. F=(q1q2)/r2

Gravity

attraction between objects that have a mass

electromagnetic force

responsible for repulsion/attraction between charged particles

as Mass Increases, gravity..

increases

As distance increases, gravity…

decreases

electromagnetic force is ____ than Gravity

stronger

____ is too weak to be detected at atomic/molecular level

Gravity

Energy

change in energy caused by changes in forces. Energy is conserved

system

the part you’re looking at

surrounding

everything else

Kinetic energy

energy of motion. KE=1/2MV2

Increase velocity =_____

increase in kinetic energy

Potential energy

stored energy.

energy can be ….

transfered and transformed

noble gasses…

do not react with anything

breaking a bond=

energy absorbed

when distance decreases electrostatic _____

is stronger

deeper PE well =

stronger interaction

Larger atomic radii =

shift right on the PE