Turn to p. 193 (Organize Elements minilab)

Cut a piece of construction paper into 10 squares and write the information for each element on each separate sheet

Follow the instructions and answer the questions on a separate sheet (one sheet per pair)

Chapter 6

J.W. Dobereiner Early 1800’s, classify elements in sets of 3

This trend didn’t work for most of the elements known at the time

Element Mass

Li 7

Na 23

K 39

1865 – noticed trend that every 8th element had same properties (law of octaves)

Unfortunately, this didn’t work for all the known elements at the time, and it was dismissed

Considered the father of the modern Periodic table

arranged by increasing atomic mass (1869)

Discovered that the # of protons = atomic number

Developed concept of arranging PT by atomic number

Periodic law – there is a periodic repetition of properties when elements are arranged by atomic #

Periods vs. groups/families

Metals vs. nonmetals vs. metalloids What are some properties? Are all nonmetals gases?

Representative elements vs. transition metals vs. inner transition metals

What do all elements in the same group have in common?

Valence electrons

All elements in the same group exhibit similar characteristics

Sodium and Potassium are both highly reactive in water

So, what subatomic particle is responsible for determining properties of an element?

How many valence electrons?

Alkali metals:

1 valence electron, s block

Alkaline earth metals:

2 valence electrons, s block

Halogens:

7 valence electrons, s and p block

Noble gases:

8 valence, totally filled s and p block, except for which element?

Helium – his s block is filled with only 2

Transition metals: (Groups 3B – 12B)

2 s-block electrons, and various d block electrons

Called transition metals b/c electrons can move around the d block

Inner transition metals:

2 s-block electrons and various f block electrons

Representative elements: (Groups 1A – 8A)

any of the s or p-block elements

Which atom has more shielding? We’ll be coming back

to this idea of shielding often

SHIELDING

Half the distance between the nuclei of 2 like atoms

No definite edge of electron cloud

atomicradius

Down the Groups What is changing about

the atom as we go down? # of shells = energy level More shells = bigger

atom

Across the Periods Same period means same

# of shells What is changing as we

go across a period?Rb

K

Na

Li

Be C F

Who is larger? Mg or S? Br or K? C or Sn?

Who is smaller? Li or N? F or I?

Put the following elements in order of increasing atomic radius

Ca, Fe, Br, O, Ba

An ion is an atom with a charge (+ or -)

In a sodium atom, how many protons and electrons do we have? How many valence e-? 11 p+ and 11 e- 1 valence e-

Can we lose protons? No, that would change the element

An atom is most stable when it has a full outer shell How many valence electrons = full?

An atom will lose or gain electrons to achieve this – whichever is easiest

Sodium has 1 valence electron. Do you think he loses or gains? Loses, then there will be 1 more proton

than electrons

If an atom has 2 valence e-, what will it do?

What group is this? What charge?

What charge does aluminum form? Lose or gain? +3, loses 3 electrons

If an ion is positive it has ______ e-

If an ion is negative it has ______ e-

Na Na+

e-

F e-F-

Who is larger? Mg or Mg2+? S or S2-? O2- or F1-?

First, determine if you have lost or gained electrons… Which particle do you have more of (who has the power?)

IE is the energy required to remove an electron from an atom (and make it an ION)

KEEP SHIELDING IN MINDBabysitter analogy

A couple First Ionization Energies:Li = 520 kJ/molO = 1310 kJ/mol

Who is harder to take an electron from?

Which has the higher ionization energy? Li or N? Cs or Li? O or S?

Which has the lower ionization energy? K or Fe? F or Br?

Warm up:As we go down the groups on the PT, the

size of the atom __________, making it __________ to take an electron away, making the ionization energy __________

As we go left to right across a period, the size of the atom _________, making the ionization energy __________.

Arrange in decreasing ionization energies:

Cr, Br, I, Li, N

How well an element can attract electrons from another element in a bond Atoms fill their outer shells when they bond

with another atom How might EN relate to IE?

If it’s hard to take an electron away, what kind of attraction do you think it has?

What do you think the electronegativity of a noble gas might be? Do they want to bond? Zero

Arrange in order of increasing electronegativity:

Mg, F, Ne, Cs, Al

UP

& OVER

IE and EN increase

RaDius Decreases

But it is good to understand the WHY so you can double check yourself…

Put in order of decreasing atomic radius:

Ca, Al, Ne, Rb, Br, Au, Zn, C

What order is this for ionization energy? (increasing or decreasing)

Skip #8

Add this question (doesn’t matter where):Determine the larger radius in the following:

a. Mg or Mg2+ (what are the the

b. Cl or Cl1- things with charges

c. Cl1- or P3- called, and how do

they get those charges?)

Between you and a partner, grab a textbook: Turn to p. 193 (Organize Elements minilab) Cut a piece of construction paper into 10

squares and write the information for each element on each separate sheet

Follow the instructions and answer the questions on a separate sheet (one sheet per pair)

When finished, turn it in and grab a BINGO card