Do Now A study was conducted about how many text messages SHS juniors send in a one hour class without getting caught. Out of 100 juniors, 94 were able

Do Now

A study was conducted about how many text messages SHS juniors send in a one hour class without getting caught. Out of 100 juniors, 94 were able to send 7 text messages, while the remaining juniors were able to send only 6 text messages.

What is the average number of text messages sent by these juniors?

How do we compute an averagenumber of texts?𝒕𝒐𝒕𝒂𝒍 ¿𝒐𝒇 𝒋𝒖𝒏𝒊𝒐𝒓𝒔=𝟏𝟎𝟎

𝒕𝒐𝒕𝒂𝒍 ¿𝒐𝒇 𝒕𝒆𝒙𝒕𝒔=?? ?

𝒂𝒗𝒆𝒓𝒂𝒈𝒆¿𝒐𝒇 𝒕𝒆𝒙𝒕𝒔=𝒕𝒐𝒕𝒂𝒍 ¿𝒐𝒇 𝒕𝒆𝒙𝒕𝒔 ¿𝒕𝒐𝒕𝒂𝒍 ¿

𝒐𝒇 𝒋𝒖𝒏𝒊𝒐𝒓𝒔 ¿

• How many juniors sent 6 texts?100 - 94 = 6• How many texts were sent by the juniors who sent 7 texts?94 juniors sent 7 texts94 x 7 = 658• How many texts were sent by the juniors who sent 6 texts6 juniors sent 6 texts6 x 6 = 36• Total # of texts = 658 + 36 = 694

How do we compute an averagenumber of texts?

𝒂𝒗𝒆𝒓𝒂𝒈𝒆¿𝒐𝒇 𝒕𝒆𝒙𝒕𝒔=𝟔𝟗𝟒𝟏𝟎𝟎

=𝟔 .𝟗𝟒

𝒕𝒐𝒕𝒂𝒍 ¿𝒐𝒇 𝒋𝒖𝒏𝒊𝒐𝒓𝒔=𝟏𝟎𝟎

𝒕𝒐𝒕𝒂𝒍 ¿𝒐𝒇 𝒕𝒆𝒙𝒕𝒔=𝟔𝟗𝟒



Announcement• Test #2 on Atomic Theory• Wednesday, November 12, 2014• 40 questions, open response • Topics

1) Creation of the Atomic Theory

2) Subatomic Particles

3) Atomic Number, Mass Number, Atomic Mass

4) Atomic Notation

Atomic Number, Mass Number & Atomic Mass

SWBAT explain the meaning of atomic number, mass number, atomic mass and atomic symbols, and determine these features using a periodic table.

Write this in your notes

Pass OutPeriodic Tables

Save your periodic tables

You will need them for tests

Do not write anything on them

8 5.1 The Atom Has a Structure

These are called subatomic particles

Atoms are made from smaller particles!

electrons

protons

neutrons

Sub-Atomic Particles

type abbrev. location in atom

relative weight charge

change in number

produces

proton p nucleus 1 +1 different element

neutron n nucleus 1 0 isotope

electron e cloud -1 ion

How do we indicate which atom we are talking about?

• There are 118 different elements• Each one can have several different isotopes

and ions• Chemists needed a way of specifying exactly

which atom they were talking about• The naming convention that evolved

specifies atoms by their subatomic particles. • Today we will start learning this naming

convention


Atomic Number

Mass Number

Atomic Symbol

Atomic Mass



Abbreviations & Equations

p = proton

e = electron

n = neutron



Atomic number

atomic number: total number of protons in a nucleus.


Atomic Number Number of protons in nucleus

Mass Number

Atomic Symbol

Atomic Mass




p = proton

e = electron

n = neutron




p = proton Np = number of protons

e = electron Ne = number of electrons

n = neutron Nn = number of neutrons







atomic number = Z = Np Write this in your notes


mass number: total number of protons and neutrons in a nucleus.

Mass number = 6 p + 6 n = 1212C

“carbon-12”Almost all of the mass of an atom

come from the protons and neutrons



Mass Number Number of protons and neutrons in nucleus

Atomic Symbol

Atomic Mass







atomic number = Z = Np

mass number = A = Np + Nn



"Normal" Atomic Symbols


"Abnormal" Atomic Symbols

Element Symbol Latin Name

Antimony Sb Stibium

Copper Cu Cuprum

Gold Au Aurum

Iron Fe Ferrum

Lead Pb Plumbum

Mercury Hg Hydragyrum

Potassium K Kalium

Silver Ag Argentum

Sodium Na Natrium

Tin Sn Stannum

Tungsten W Wolfram

Argentum

Argentina


atomic symbol: One or two letter abbreviation for each element



Mass Number Number of protons and neutrons (nucleons) in nucleus

Atomic Symbol 1-2 letter abbreviation for element name

Atomic Mass



Capitalization

• The first letter of an atomic symbol is capitalized

• If there is a second letter, it is not capitalized

• Co = cobalt• CO = carbon & oxygen

• Cl = chlorine Cl• CI = carbon & iodine CI



• Get out your periodic table

• Find lithium (atomic symbol is Li)

• How many protons does it have?

• How many neutrons does it have?


How can lithium have 0.941 neutrons?

Periodic Table Notation


Two lithium isotopes in nature



What is the massof each atom?



Mass number of this atom3 + 3 = 6





6% of natural abundance


94% of natural abundance


If we randomly selected 100 lithium atoms from nature, their MASS NUMBERS would be:

It’s an AVERAGE mass!

Atomic Mass


Remember the "Do Now"

𝒂𝒗𝒆𝒓𝒂𝒈𝒆¿𝒐𝒇 𝒕𝒆𝒙𝒕𝒔=𝟔𝟗𝟒𝟏𝟎𝟎

=𝟔 .𝟗𝟒

𝒕𝒐𝒕𝒂𝒍 ¿𝒐𝒇 𝒋𝒖𝒏𝒊𝒐𝒓𝒔=𝟏𝟎𝟎

𝒕𝒐𝒕𝒂𝒍 ¿𝒐𝒇 𝒕𝒆𝒙𝒕𝒔=𝟔𝟗𝟒





Atomic Mass

Why is this on the periodic table???• 6.941 g is one mole of lithium

– one mole is 6.022 x 1023 molecules– 6,022,000,000,000,000,000,000

• Chemists use this number to figure out how many molecules they have

Periodic Table Notation



Atomic Mass

Mass Number of this atom3 + 3 = 6

Mass Number of this atom3 + 4 = 7





Atomic Mass Mass of element weighted according to natural abundance


Calculating Atomic Charge

charge = 8 ‒ 10 = ‒2 (anion)

charge = 11 ‒ 11 = 0

charge = 11 ‒ 10 = +1 (cation)

charge = Np ‒ Ne

If you are given the charge,

remember Np is determined by the element







charge = Np - Ne



Homework on Atomic Theory

• Textbook pgs 128-129• Problems 37, 42, 48, 51, 61

64, 65, 67, 68, 71

Check for Understanding

A new element has been discovered. It has an atomic number of 119 and a symbol of Uun. It has two different isotopes. The isotope with 178 neutrons has an abundance of 62.00%, while the remaining abundance is from an isotope with 181 neutrons.

What is the atomic mass of Uun?

How do we compute anatomic mass?

𝒕𝒐𝒕𝒂𝒍𝒎𝒂𝒔𝒔=?? ?¿𝒐𝒇 𝒂𝒕𝒐𝒎𝒔=? ??

𝒂𝒕𝒐𝒎𝒊𝒄𝒎𝒂𝒔𝒔=𝒕𝒐𝒕𝒂𝒍𝒎𝒂𝒔𝒔¿𝒐𝒇 𝒂𝒕𝒐𝒎𝒔

𝒂𝒕𝒐𝒎𝒊𝒄𝒎𝒂𝒔𝒔=?? ?

• Imagine we have a 100 atoms# of atoms = 100




𝒂𝒕𝒐𝒎𝒊𝒄𝒎𝒂𝒔𝒔=?? ?

¿𝒐𝒇 𝒂𝒕𝒐𝒎𝒔=𝟏𝟎𝟎

• How do we calculate the total mass of 100 atoms?add up the masses of all the isotopes• How do we calculate the mass of each isotope?(mass number of isotope) x (abundance of isotope)

• What is the mass number of the isotope with 178 neutrons? A = Np + NnNn = 178Np = ???• What is the number of protons of the new element?atomic number = 119Z = Np = 119

A = 119 + 178 = 297 calledUun-297

• What is the mass number of the isotope with 181 neutrons? A = Np + NnNn = 181Np = 119A = 119 + 181 = 300 calledUun-300

• Imagine we have a 100 atoms# of atoms = 100• How many of these atoms are Uun-297?"abundance is 62.00"so 62 atoms are Uun-297• How many of these atoms are Uun-300?"the remaining abundance"100 - 62 = 38so 38 atoms are Uun-300

• How do we calculate the mass of each isotope?(A of isotope) x (abundance of isotope)• What is mass of Uun-297?(A of Uun-297) x (abundance of Uun-297)(297) x (62)• What is mass of Uun-300?(A of Uun-300) x (abundance of Uun-297)(300) x (38)

• How do we calculate the total mass of 100 atoms?add up the masses of all the isotopes(297) x (62) + (300) x (38)

¿𝒐𝒇 𝒂𝒕𝒐𝒎𝒔=𝟏𝟎𝟎


𝒕𝒐𝒕𝒂𝒍𝒎𝒂𝒔𝒔=?? ?


𝒂𝒕𝒐𝒎𝒊𝒄𝒎𝒂𝒔𝒔=?? ?𝒕𝒐𝒕𝒂𝒍𝒎𝒂𝒔𝒔=(297) x (62) + (300) x (38)


𝒂𝒕𝒐𝒎𝒊𝒄𝒎𝒂𝒔𝒔=(297) x (62) + (300) x (38)

𝟏𝟎𝟎

𝒂𝒕𝒐𝒎𝒊𝒄𝒎𝒂𝒔𝒔=(18414 ) + (11400 )

𝟏𝟎𝟎

𝒂𝒕𝒐𝒎𝒊𝒄𝒎𝒂𝒔𝒔=29814𝟏𝟎𝟎

𝒂𝒕𝒐𝒎𝒊𝒄𝒎𝒂𝒔𝒔=𝟐𝟗𝟖 .𝟏𝟒 How many sig figs?



What is the atomic mass of Uun?


𝒂𝒕𝒐𝒎𝒊𝒄𝒎𝒂𝒔𝒔=(297) x (62) + (300) x (38)

𝟏𝟎𝟎

𝒂𝒕𝒐𝒎𝒊𝒄𝒎𝒂𝒔𝒔 ≅𝟐𝟗𝟖 .𝟏

𝒂𝒕𝒐𝒎𝒊𝒄𝒎𝒂𝒔𝒔=(18414 ) + (11400 )

𝟏𝟎𝟎

𝒂𝒕𝒐𝒎𝒊𝒄𝒎𝒂𝒔𝒔=29814𝟏𝟎𝟎

𝒂𝒕𝒐𝒎𝒊𝒄𝒎𝒂𝒔𝒔=𝟐𝟗𝟖 .𝟏𝟒 4 sig figs



What is the atomic mass of Uun? 𝟐𝟗𝟖 .𝟏

Review of Objective

SWBAT explain the meaning of atomic number, mass number, atomic mass and atomic symbols, and determine these features using a periodic table.




Atomic Mass Mass of element weighted according to natural abundance







charge = Np - Ne


Potassium has two isotopes, potassium-39 & potassium-41. If the atomic mass is 39.10, what is the natural abundance of each isotope?X = abundance of A = 39

1 – X = abundance of A = 41

39.10 = (X)(39) + (1–X)(41)

39.10 = 39X + 41 – 41X

39.10 = –2X + 41

–1.90 = –2X

0.95 = X

95% A = 39, 5% A = 41




𝒂𝒕𝒐𝒎𝒊𝒄𝒎𝒂𝒔𝒔=𝟑𝟗 .𝟏𝟎

• Imagine we have a 100 atoms# of atoms = 100


𝒕𝒐𝒕𝒂𝒍𝒎𝒂𝒔𝒔=?? ?¿𝒐𝒇 𝒂𝒕𝒐𝒎𝒔=𝟏𝟎𝟎



• Imagine we have a 100 atoms# of atoms = 100• Set the # of potassium-39 atoms to be "y"# of potassium-39 = y• The # of potassium-41 would be "100 - y"# of potassium-41 = 100 - y

• The mass of all the potassium-39 atoms is found as follows:(# of potassium-39) x (mass of potassium-39)(y) x (39)39y• The mass of all the potassium-41 atoms is found as follows:(# of potassium-41) x (mass of potassium-41)(100 ‒ y) x (41)4100 ‒ 41y

• The total mass of all the potassium atoms is found as follows: total mass of potassium-39 + total mass of potassium-41total mass of potassium atoms 39y + 4100 ‒ 41y4100 ‒ 2 y


𝒕𝒐𝒕𝒂𝒍𝒎𝒂𝒔𝒔=𝟒𝟏𝟎𝟎 ‒𝟐 𝒚¿𝒐𝒇 𝒂𝒕𝒐𝒎𝒔=𝟏𝟎𝟎


𝟑𝟗 .𝟏𝟎=𝟒𝟏𝟎𝟎 ‒𝟐 𝒚

𝟏𝟎𝟎


−𝟏𝟗𝟎=‒𝟐 𝒚

𝟑𝟗 .𝟏𝟎=𝟒𝟏𝟎𝟎 ‒𝟐 𝒚

𝟏𝟎𝟎

𝟑𝟗𝟏𝟎=𝟒𝟏𝟎𝟎 ‒𝟐 𝒚

𝟗𝟓=𝒚

• Set the # of potassium-39 atoms to be "y"# of potassium-39 = y or 95% are potassium-39• The # of potassium-41 would be "100 - y"# of potassium-41 = 100 - y100 - 95 = 5 or 5% are potassium-41

Weighted Average

Documents

Do Now A study was conducted about how many text messages SHS juniors send in a one hour class without getting caught. Out of 100 juniors, 94 were able