×
Log in to StudySoup
Get Full Access to AU - CHEM 1030 - Class Notes - Week 2
Join StudySoup for FREE
Get Full Access to AU - CHEM 1030 - Class Notes - Week 2

Already have an account? Login here
×
Reset your password

AU / Chemistry / CHEM 1030 / What is subatomic particle?

What is subatomic particle?

What is subatomic particle?

Description

School: Auburn University
Department: Chemistry
Course: Fundamentals Chemistry I
Professor: John gorden
Term: Fall 2015
Tags: CHEM1030, Chemistry, and Blumenthal
Cost: 25
Name: CHEM 1030 Chapter 2 Lecture Notes
Description: These notes include the chapter 2 notes lectured by Dr. Blumenthal. They are a little sloppy, but I decided to write them since there were so many diagrams in the lecture. I hope you guys can still understand them if they aren't neatly typed.
Uploaded: 09/07/2016
11 Pages 73 Views 4 Unlocks
Reviews


SHEM 1630- Rik Blumenthal Chapter 2 Lecture Notes


What is subatomic particles?



Homs and the Periodic Table

Atom: smallest quantity of matter

ou still retaining properties of

the matter art

Atoms are made of subatomic particles - electrons, protons neutron

The discovery of subatomic particles was product of research involving radiation'

Cemission & transmission of energy


What is the cathode ray tube?



through waves)

Subatomic Particles & Atomic structure

•1800s - research involving radiation

w/ "new toys' on

•Cathode Ray Tube (5.5. Thomson): DISCOVERY OF ELECTIONS otwo metal plates negatively (-) and positively (+) charged

sealed in glass tube z a connected to voltage source. o(-) charged plate - cathode - emits cathode ray (stream


The magnitude of electric field is necessary for what?



We also discuss several other topics like What is the central dogma?

of (-) charged particles

o Cathode raymoves towards (t) charged plate - anede. We also discuss several other topics like Where is timbuktu located?
If you want to learn more check out What is the period of relaxation in the heart?

*SE E PICTURE ON NEXT PAGE

causes cathode Trays to glow

.

.

.

...

..

.

Cathode

-

Cathode

1. Rays

o placing the different poles of a magnet mear Don't forget about the age old question of What temperature has a numerical value that is the same in degree celsius as it is in degree fahrenheit?

visible cathode rays can show what the cathode

rays' charge is * If the ray deflects the positive end of magnet,

it must be positively charged. If it attracts the u se end of magnet, it must be negatively charged (Based on Coulomb's Law: LIKE repels LIKE

- OPPOSITE attracts OPPOSIT The cathode rays deflected (-) end and attracted (t) e If you want to learn more check out Sleep restores what?

- We also discuss several other topics like What is cosmological principle?

-

-

so

......

.

......

&cathode rays must be made of (-) charged partic

I later named electrons. o In a similar experiment, Thanson used two electric

plates (+) n (-) charged and the ray again deflected by the (-) plate and attracted by the (+) plate

V* SAME CONCLUSION

•After discovering electrons, Thomson Imeasured degree of deflection of cathode rays

Determined charge-to-mass ratio of electrons]

-1.76 *10* Cly (coulomb's gram)

1909 Robert Millikan perform's le Oil drop experiment to

determine charge and mass of electron.

• Oil droplets placed in enclosed box w/ electric field

Drops picked up static charge from surrounding air

• Drops were suspended (floating") in the electric

The magnitude of electric field necessary to keep drop Suspended depended on amount of charge the drop got from the air. from this, Millikan discovered charge of hatron

1 = -1.60 22x10-19 C

He then used charge to-mass ratio to convert charge to mass: Mass of electron = 9.10*10-28

V

.

e

w

..

..

.

...

.

.

A

*SEE PICTURE ON NEXT PAGE

Oil drops

Electric

Field

Oil drops

Suspended

..."

BABA

...

YN

.

.

.

..

......

ww....

.

........4

.

*

nen

..

.

..

.

...

14.

0

w

N

.

***

..

..

..

****

...

******

.

.

w

U

•Radioactivity: spontaneous emission of radiation

More experimentation w/ cathode rays revealed 3 types of radiation

Henri Becquerel discovered some rocks emit radiation Ispontaneously (on their own) & concluded 3 types of radiation to be

Alpha Rays (2) -positively charged © Beta Rays (3) - regatively charged 3 Gamma Rays (8) - neutral charge

- Proposed Models of Atom

*****

.

ww.

.

**

..

.

***

••••••

..

*

w

*

After Thomson's cathode ray experiment he proposed "Plum - Pudding Model of atomic structure:

SEO

electrons

o

harges to cancel out

embedded

positively charged area * It was already known atoms had

(-) charged particles, but atams are neutral, so they must have positive

elant (-) charges Thomson proposed electrons

charged matter. Thomson's model later dispproved by Ernest Rutherford's . Gold Foil Experiment Emitted Alpha particles (f) to thin sheet of gold foil

If Thomson's model is correct (meaning if atants had uniformly distributed (t) particles) o.

THEN j particles should be mostly deflected

Thomson Prin mass of positively embedded in m

1

.

and very few were completely deflected *Rutherford concluded

Atams must be made of mostly "empty space,"

or electron-filled space Lectroms

AND filempty spa There must be smallenbedd area

of positive particles- later named protons concentrated in center of atan bestelle

..

.ON

..

*

.

.

.

***

(+)

To Proton mass = 1.672 62 x 104 g 7 taldo Proton charge = 1.6022*10c

(same and opposite of election

- charge). Neutrons * Electrons & protons did not account for total mass of an

atom.

so

There must be other particles that are neutral contributing to a mass Neutron Mass: 1.67498+104]

-

.

NA

.

.

**

..

M.

..

..

..

...

**

.

***

...

--

Uledesca Atomic Number, Mass Number

Atomic number of an element is the # of protons and electrons of an element (since protons & electrons cancel out,

Protons define an elehere must be an equal #of both Ex. All Nitrogen atoms have ? protons

land ? electrons) Atomic mass is # of Neutrons + # of protons)

on

* Here is how atanic

a periodic table:

# and mass are notated

Atomic #

....

Atanic mass

Notating atomic # and mass:

LA

atamic.

mass

A un element

symbol

Alamict

.

..

* Although atoms of same element have same atomic #

. (# of protons) atoms of same element can have different atomic

• Isotgeesiatoms w/ same atomic # but different

w #of neutrons therefore different atomic ma Ex Hydrogen has 3 isotopes

Hydrogen

Denterium

• How isotopes were discovered:

Two nuclei of same element were deflected by electric field BUT by different amounts

of deflection

nuçleus

nucleus

GL

대가

*The different degrees of deflection show there

med must be a different amount of con (+)

particles (neutrons) causing one isotope to be more attracted to the negative pole.

- Average Atomic Mass

measured in Average Mass Units Camu) ilamu = l. Cl 05 388*10*9947 he Calculating en Average Atomic Mass in amus

*Since elements naturally occur in different isotopes,

the masses of each isotope are averaged together to find Average Atanic Mass.

*

**

*

.

*

Average Atomic Mass = f,M, + f2M27 of a fraction representing natural abundance of

. isotope this is usually a percentage givenablem) M = mass # of isotope

oblem

Practice Problem Find the average atanic mass of 50% Li

B and

507. 'Li *The fraction of "Li abundance is 50 or 150

The mass is 6. * The fraction of "Li abundance is 5000 or 50

The mass is ?

**.

so

ang atomic praf, M, +f, MA = (50) (1) + (50) () = 6.5 amu

.

SO

A Mole is a unit, (mol) It tells how many atoms are in a

sample of something

mitaceodathing mol = 6,022 x 1023 atoms Avagadro's Number

*Similar to how a dozen = 12 of somethi

Molar Mass on tells you the mass in grams of Imal of substance

units for molar mass are glmal

lamu is defined as Iglmal (lamu= Ig/mol) Ex. If the average atomic mass of legend is 1.00794 amn, then 1.00794 amu=1.00294 g/mol

AND If the average atomic mass of chlorine (CI) is 35.453 amu, then 35.453 amu = 35.453 g/mol

VIL

average

.

Practice Problem

(Molar Mass)

www

. If there are 50.0 g Felg) in how much Clzig) is there?

FeCl (s),

1 First, turn 50.0g

into mol Fe.

Fe

50. Og Fe Imel

E = .8953 ml Fe 55.843. Fe

The mass

-

Fe is taken from

3 Turn .8953 mol Fe

into mal cl

1

the

periodic

I

table

8953mol Fe 3 - Imol Cl. 2.686 mol cl

T. Tmel Fe Turn 2686 ml Cl Taken from able into gCl

2.686 mol Cl 35.453C1-Ja5.

Imol el

Cl2/

Page Expired
5off
It looks like your free minutes have expired! Lucky for you we have all the content you need, just sign up here