Warm UpWarm Up 9-21-159-21-151. Convert 25 mg to g

2. How many neutrons are in 85Kr?

3. Write the short hand electron configuration for Indium and Bromine

HomeworkSept 23 - Test unit 2Sept 23 - Notebook check (6 days of notes for unit 2)

AgendaTurn in WS Test reviewNotes Unit 3-1WS Subatomic heavyweights

Unit 3-1Unit 3-1The Periodic TableThe Periodic Table

How would you organize the How would you organize the following (16) items?following (16) items?

Wrench

Pliers

Clamp

Nuts

Drill

Screwdriver

Boxcutter

allenwrench

Unit 3-1Unit 3-1Periodic LawPeriodic Law

Periodic law Periodic law - periodic - periodic table is organized based table is organized based on the on the atomic #atomic #, chemical , chemical & physical properties of & physical properties of the elementsthe elements

Mendeleev is the creator Mendeleev is the creator of the periodic table used of the periodic table used atomic massatomic mass

The Periodic TableThe Periodic Table

Group or familyGroup or family A vertical columnsA vertical columns Elements in a group share the same chemical Elements in a group share the same chemical

propertiesproperties

PeriodPeriod A horizontal rows A horizontal rows Elements in the same period have the same Elements in the same period have the same

number of energy levelsnumber of energy levels

The Periodic TableThe Periodic Table Elements’ chemical properties are Elements’ chemical properties are

determined by the number of valence determined by the number of valence electrons electrons

Valence electrons Valence electrons are electrons that are in are electrons that are in the outermost energy level of an atom the outermost energy level of an atom (in the S and P orbital only)(in the S and P orbital only)

e- e-e- e- e-

e-

The Periodic TableThe Periodic Table

Average Atomic Mass vs. Mass Average Atomic Mass vs. Mass NumberNumber

What is the mass of neon element?

Average Atomic Mass vs. Mass Average Atomic Mass vs. Mass NumberNumber

The The average atomic average atomic mass is the average of mass is the average of the mass numbers of all the isotopes of the mass numbers of all the isotopes of that element.that element.

Molybdenum Molybdenum probably probably has more isotopes with a mass has more isotopes with a mass number of 96, rather than 95number of 96, rather than 95

Average Atomic Mass and Mass Average Atomic Mass and Mass NumberNumber

Name of Atom

Abundance Percent %

Mass x Percent

Lead-204 1.4 204 x 0.014 = 2.856

Lead-206 24.1 206 x 0.241 = 49.646

Lead-207 22.1 207 x 0.221 = 45.747

Lead-208 52.4 208 x 0.524 = 108.992

What is the average mass of Lead? Based on the given stable isotopes

AssignmentsAssignments

SummarySummary WS Subatomic heavyweights due todayWS Subatomic heavyweights due today Study for Unit 2 test WednesdayStudy for Unit 2 test Wednesday