1. The Periodic Table

2. Mendeleev and Chemical Periodicity
when the elements were arranged in order of increasing atomic mass, similarities in their chemical properties appeared at regular intervals.
Repeating patterns are periodic.
created a table
elements with similar properties were grouped together

3. Several empty spaces were left. In 1871
predicted the existence and properties of elements that would fill five of the spaces.
By 1886, three had been discovered. Ga Sc Ge

5. Modern Periodic Table
The Periodic Table is an arrangement of the elements in order of their atomic numbers so that elements with similar properties fall in the same column, or group.

6. Periods and Blocks
Elements in the same column (group or family) share similar chemical properties.
Elements are also in rows, (periods)
The length of each period is determined by the number of electrons that can occupy the sublevels being filled
The periodic table is divided into four blocks, the s, p, d, and f blocks.
The name refers to the electron sublevel being filled the block.

7. Blocks of the Periodic Table

8. Valence Electrons and Ions
e- in outer most energy level
Octet Rule
Atoms gain, lose, or share valence e- to have full outer energy level (8 valence e-)
Ions- atoms of an element with different numbers of protons and electrons
Gain e- atom becomes negative
Loose e- atom becomes positive

9. Alkali metals Group 1 known as the alkali metals
lithium, sodium, potassium, rubidium, cesium, and francium
In their pure state
a silvery appearance
soft enough to cut with a knife
Not found in nature in pure form
Each has 1 valence electron
Each makes a 1+ ion

10. Alkaline Earth Metals Alkaline earth metals
Group 2 are called the alkaline-earth metals
beryllium, magnesium, calcium, strontium, barium, and radium
Alkaline earth metals
less reactive than the alkali metals,
still too reactive to be found in nature in pure form.
Each has 2 valence electrons
Each makes a 2+ ion

11. Transition Elements Metals in groups 3-12 Typical metallic properties
Make many different ions

12. Halogens Group 17 known as the halogens
fluorine, chlorine, bromine, iodine, and astatine
Halogens
Most reactive nonmetals.
React vigorously with most metals to form salts
Each has 7 valence electrons
Each makes 1- ions

13. Noble Gases Group 18 known as noble gases
Helium, neon, argon, krypton, xenon, and radon
Halogens
Most non-reactive elements
Have 8 valence electrons
Do not form ions

14. f-block The 1st row of the f block known as the lanthanides
Lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium. Erbium, thulium, ytterbium, lutetium
lanthanides
shiny metals
reactivity like alkaline earth metals.

15. The 2nd row of the f block known as the actinides
actinium, thorium, protactinium, uranium, neptunium, plutonium, americium, curium, berkelium, californium, einsteinium, fermium, mendelevium, nobelium, lawrencium
Actinides
The actinides are all radioactive

16. Main Group Elements

17. Metals, Nonmetals, Metalloids

18. Metals Conductors of heat and electricity Ductile Malleable
Solid at room temp (except Hg)
React with acids
To left of stair-step line including the f-block

19. Nonmetals Do not conduct heat or electricity Brittle
Usually gas or liquid at room temp
To right of stair-step line

20. Metalloids Have properties of both metals and nonmetals
On either side of the stair-step line