RESOURCES SECTION BPeriodic Trends

• Why are the elements placed the way they are on the periodic table?

PERIODIC TABLE - DEVELOPMENT

John Dalton

Dalton’s periodic table

What are the physical and chemical properties of:

• METALS

• NON-METALS

• METALLOIDS

How do you determine which category (metal, non-metal, or metalloid) the

elements are in from the Periodic Table?

Who is considered the father of the Periodic

Table?• In what two major ways did he organize the

elements known at the time?– Increasing atomic mass– The way they combine with other elements

• How was he able to determine that there were elements “missing” that had not even been discovered yet?

• How was Mendeleev’s original Periodic Table different from the modern Periodic Table that we use today?

Mendeleev

Mendeleev’s Periodic Table

There are two numbers given in each square for each element on all Periodic

Tables, what are they, what do they mean, and how can you tell them apart?

ATOMIC NUMBER: The whole number, tells how many protons in the element (and thus electrons)MASS NUMBER: The non-whole number, tells the mass of the element (protons + neutrons)

3Li

6.941

Practice #1

• How many total electrons does a neutral Magnesium atom have? • 12

• What about Silicon?• 14

• How many protons in Bromine?• 35

• How many neutrons in Krypton?• 48

Why is the periodic table arranged the way it is?

• Notice in a neutral atom the # of electrons = # of protons.

• Sodium has 11 negative charges and 11 positive charges.

Na

Alkali

Metals

Alkaline E

arth M

etals

Transition Metals

Halogens

Noble G

ases

Lanthanide and Actinide

NEW ELEMENTS!!•

WOMANIUM (WO) Physical properties: Generally soft and round in form. Boils at nothing and may freeze any time. Very bitter if not used well. Chemical properties: Very active and highly unstable. Possesses strong affinity with gold, silver, platinum, and precious stones.. Turns slightly green when placed next to a better specimen. Usage: An extremely good catalyst for dispersion of wealth. Caution: Violent when left alone

• MANIUM (XY) Physical properties: Solid at room temperature but gets bent out of shape easily. Difficult to find a pure sample. Chemical properties: Attempts to bond with WO any chance it can get. Becomes explosive when mixed with Childrium for prolonged period of time. Usage: Possibly good methane source. Caution: In the absence of WO, this element rapidly decomposes and begins to smell.

•

PARTICLE LOCATION CHARGE MASS

Protonnucleus

 +1 amu

Neutron nucleus 0 1 amu 

Electron Outside nucleus  - 0.00054 amu 

Subatomic Particles

Symbol Name Protons (Atomic Number)

Neutrons Mass Number

Electrons

73Li  Lithium -7  3   4 7  3 

146 C Carbon-14   6 8  14 6

6731Ga Gallium -67 31  36 67  31 

           

           

Common Isotopes

Isotopes of Particular interest –C-14 used in radiocarbon dating I-131 used in thyroid cancer treatmentU-235 used in nuclear power

Why is the periodic table arranged the way it is?

Why is the periodic table arranged the way it is?

• Sodium (Na) has one electron in its outermost shell.

•So do all the other elements in Group 1A.

Na

Practice #1

• How many electrons does Magnesium have in its outer shell? • 2

• What about Silicon?• 4

• Bromine?• 7

• Neon?• 8

USING AN ACTIVITY SERIES• Activity series can be used to determine whether a single replacement reaction will occur ….or not• Stronger elements (above other elements on the chart) will replace weaker ones (below other elements on the chart) in a “relationship”

Link to Activity Series

LINK TO TYPES OF REACTIONS

1. COMBINATION (Synthesis)A + B = AB

2. DECOMPOSITIONAB = A + B

3. SINGLE REPLACEMENTA + BC = AC + B• Use Activity Series to Determine if this will

occur4. DOUBLE REPLACEMENT

AB + CD = AD + CB• Use Solubility Table to determine Precipitiate

formation5. COMBUSTION

CxHy + O2 = CO2 + H2OA + O2 = AxOy

USING AN ACTIVITY SERIES• Activity series can be used to determine whether a single replacement reaction will occur ….or not• Stronger elements (above other elements on the chart) will replace weaker ones (below other elements on the chart) in a “relationship”

Link to Activity Series

Example: Cu + Ag(NO3) Cu(NO3) + Ag