“Unknown” element, Rx, is a non metalRx has similar chemical properties to

Fluorine (F) and Iodine (I). Rx’s atomic # is greater than Argon (Ar),

but less than Krypton (Kr).

What element must Rx be?

Non metalsAre In this cornerIn green

Trends are: Predictable ways in which something changes

Atomic Radius Trend in the size of an atom

Ionic Radius Trend in the size of ions of an atom

Periodic Table Trends

An atom’s size is determined by the space occupied by its e- cloud

Generally decreasesGenerally decreases

Size of atoms of elements of the periodic table (atomic radius)

Atomic radius: see if you can tell who is bigger?

1. Put Group 2 in order Smallest to largest:Sr Be Mg Ca

2. Put Group 1 in order Smallest to largest:Na Li H K Rb

3. Put these elementsFrom Period 5 in order smallest To largest: Xe Cd Mo Zr Rb

A trend is a predictable change you can see. So fill in the blanks with the choices:As you go down a group (column) the atomic radius (increases/decreases) ______________________. As you go across a period (row) the atomic radius(increases/decreases) ____________________.

What do you notice as you move from left to right?

Do you have more or less e- as you move from left to right?

The size _________ because:

The atomic radius gets smaller as you move from left to right

•Elements in the same period have the same highest (principal) energy level. •e- AND protons are added (atomic # increases)

•Nucleus has more power to pull e- in principal energy level closer to nucleus (= smaller radius)

decreases

Less e-

What trend(s) do you notice as you move from top to bottom?

Do you have more or less e- as you move from top to bottom?

The atomic radius gets _________ because:

The atomic radius gets larger as you move from top to bottom

More

larger

Each atom has the same # of e- in their valence shell, but the highest (principal) energy level has increased by 1 each time you move down. (You would need to draw an additional shell around the nucleus.)

Using only your notes and a periodic table, which would have a bigger atomic radius?

He / Ar

K / Ar

Fe / Br

Ar

K

Fe

Mg / S Mg

Size of radius of an atom after it has gained or lost electrons to get a full shell (lucky 8). Remember: Stability is achieved by having a full valence shell.

The ionic radius becomes: Smaller = When e- are lost Larger = When e- are gained

e- gainede- lost

A trend is a predicable pattern. Which is a trend:1. Ion size increases L to R across a period2. Ion size increases top to bottom for groups 1 and 2

Energy Level

Element # 1ELECTRONS

Element # 2ELECTRONS

Element # 3ELECTRONS

1st 1s

2 2 2

2nd 2s 2p

8 8 8

3rd

3s 3p1 6 8

1. Can you tell what elements are shown here?2. Can you tell which is a noble gas and which is an alkali metal?3. How could you tell which one is a metal?

Metals- Loose e- easily!Good conductorshigh luster or sheenSolid at room

temperature (except Mercury)

Ductile- drawn into wire

Malleable- Able to bend, hammered into thin sheets without breaking

Nonmetals- Poor conductors

(Carbon is exception)Most are gases at

room temperatureProperties opposite of

metals. Non-malleable Non-ductile

Brittle (break easily)

Metalloids- Properties similar to

both metals and nonmetals

Depends on the conditions Temperature Pressure

Found where the metals and nonmetals meet on the periodic table.

Atom #Protons

#Electrons

#Neutrons

1 11 11 12

2 13 13 13

3 12 12 11

4 11 11 11

1. How many elements are shown here?2. Are any of these isotopes of each other?3. How can you tell?

BrainPop! http://www.brainpop.com/science/matterandchemistry/isotopes/

Ions are formed when an atom gains or looses: protons neutrons e-

Isotopes are formed when an atom looses: protons neutrons e-

What is formed when an atom looses a proton? A different element! Remember: The atomic # is determined by the # of

protons in an atom’s nucleus!

Naturally occur, some more common than others

The atomic mass of an element is determined by looking at the abundance of these different isotopes and calculating the average.

THIS is why the atomic mass for the elements is not a whole #!!

Atomic # on Atomic # on bottombottom

Mass #Mass #