Lesson 13The Periodic Table

Do Now 6S, O, Ga 12.14.18Copy info down into CJ. Keep CJs out and open on desk throughout class.

On Do Now Page #7, copy and answer:

1. If an object with a mass of 11.2 g displaces 3.42 mL of water, what is its density?

2. What is the density of pure water?

3. Draw & label a particle diagram of a mixture of elements.

4. Draw & label a particle diagram of a mixture of compounds.

Do Now 6O, S 12.19.18Take out HW from last class and signed tests.

Copy info down into CJ. Keep CJs out and open on desk throughout class.

On Do Now Page

1. Copy and identify each element:a) Same period as strontium, 5 valence electrons

b) Similar properties to fluorine, 4 electron shells

c) 3 valence electrons, 3 electron shells

d) A metalloid with 3 valence electrons

2. Density = 1.02 g/mL, Mass = 489 dg, Volume = ?

Do Now 6S, 6O 12.20.18Take out quiz corrections to be collected.

Copy info down into CJ. Keep CJs out and open on desk throughout class.

On Do Now Page #8: copy and answer – show all work with units.

1. M = 20.1 g, D = 0.98 g/mL, volume in mL = ?

2. V = 128.2 cL, M = 38.2 g, density in g/L = ?

Do Now 6S, 6O Jan 10th, 2019

Copy info down into CJ. Keep CJs out and open on desk throughout class. Take out your HW to be collected.

On Do Now Page #8, copy and answer:

1. If you want to separate iron fillings from sand, you would use a _____.

2. Some solutions, such as salt water, are separated by which process?

3. Suspensions are best separated by which separation technique?

4. If V = 100 mL and D = 3.45 g/mL, M = ?

Do Now 6S, 6O, Ga Jan 11th, 2019

Copy info down into CJ. Keep CJs out and open on desk throughout class.

On Do Now Page #8, copy and answer:

1. How are 5Li and 6Li the same? How are they different?

2. Which techniques should be used to get salt from a dry mixture of salt and sand?

3. If M = 1,000. mg and D = 5.25 g/mL, V = ?

Videos:https://www.youtube.com/watch?v=uixxJtJPVXk

Alkali metals in water

https://www.youtube.com/watch?v=fPnwBITSmgU

Genius of Periodic table

https://www.youtube.com/watch?v=yQP4UJhNn0I&t=223s

How small is an atom?

Changing Atomic Models

https://www.researchgate.net/figure/The-atomic-models-timeline-sorted-by-the-year-they-were-proposed_fig12_318027503

Early Experimentation

Ernest Rutherford

Gold Foil Experiment

α particles consist of two protons and two neutrons

Ernest Rutherford

Gold Foil Experiment

“It was quite the most incredible event that has ever happened to me in my life. It was almost as incredible as if you fired a 15-inch shell at a piece of tissue paper and it came back and hit you”[1]

Ernest Rutherford, “The Development of the Theory of Atomic Structure,” ed. J. A. Ratcliffe, in Background to

Modern Science, eds. Joseph Needham and Walter Pagel, (Cambridge, UK: Cambridge University Press,

1938), 61–74. Accessed September 22, 2014,

https://ia600508.us.archive.org/3/items/backgroundtomode032734mbp/backgroundtomode032734mbp.pdf.

Ernest Rutherford

Gold Foil Experiment

Analyzing Isotopes

Lesson Slides:

History

• Dmitri Mendeleev developed the first Periodic Table.

• He organized elements by property, then put them into group according to their mass.

• Henry G.J. Moseley arranged elements by atomic number (# of protons)

• Periodic law: Physical and chemical properties recur in a systematic matter when

elements are placed by increasing atomic number.

Periodic Table TodayToday, the Periodic table is arranged by increasing atomic number (# of protons)

On each panel representing elements you will see◦ Name of element

◦ Atomic number

◦ Average atomic mass (usually a decimal number, represents the average of all the naturally-occurring isotopes of each element)

Periods of the Periodic Table

• Period = row on the periodic table

• Elements in the same period have the same number of electron shells or

energy levels.

• Period # = number of electron shells

• Elements in the same period do not all have the same properties.

Families of the Periodic TableGroup / Family = column on the Periodic table

Elements in a group have similar reactivity and properties.

Valence electrons = electrons in the outermost electron shell (farthest from nucleus).◦ # of valence electrons = group # (for A group only)

Some groups/families have names.

We refer to the groups/families by number or letter and number.

Example: Lithium is in group 1A, or group 1, also known as the Alkali metal family

PERIODS correspond to number of electron shells

1

2

3

4

5

6

7

GROUPs correspond to number of valence electrons

12 3 4 5 6 7

8A group

Families of the Periodic Table

1A

one

shiny

soft

Very reactive

H

Video: Alkali metals react with water

https://www.youtube.com/watch?v=uixxJtJPVXk

2A

two

Solid

Very reactive,

7A

seven

Most reactive

(diatomic)

At so

study it

8A

8

Stable / unreactive

Colorless, odorless

B Transition metals

One or two

shiny dense

Melting points

Hg (mercury) is liquid at room temperature

Lanthanides

Rare earth metals

Manufacturing, metal alloys, magnets

Actinides

synthetic

All radioactive (unstable)

ElectronsElectrons in the outermost electron shell

Have the highest energy

Group A #

1-2

Chemical bonding

All other electrons that are not in the outermost shell

Total electrons valence electrons

Have lower energy than valence electrons; are closer to nucleus

PRACTICE: How many total, valence, and core electrons do the following neutral elements have?

Element Name Total electrons Valence electrons Core electrons

Li

N

Cl

Sr

F

Mg

K

Se

PRACTICE: How many total, valence, and core electrons do the following neutral elements have?

Element Name Total electrons Valence electrons Core electrons

Li 3 1 3-1 = 2

N 7 5 7-5 = 2

Cl 17 7 17-7 = 10

Sr 38 2 38-2 = 36

F 9 7 9-7 = 2

Mg 12 2 12-2 = 10

K 19 1 19-1 = 18

Se 34 6 34-6 = 28