1. Organization of The Periodic Table

2. Nucleus Center of the atom. Makes majority of the atom’s mass.
Made of Protons and Neutrons.
Nucleus

3. Protons
Part of the nucleus
Have positive (+) charge

4. Neutrons
Part of the nucleus
Have neutral charge

5. Electrons
Orbit around the nucleus
Have negative (-) charge

6. Atomic Number Definition: the number of protons in the nucleus
Tells us the identity of the element.
Every element is defined by the number of protons in its nucleus

7. Isotopes
Atoms with the same number of protons but different numbers on neutrons
Example: Carbon
So you can change the number of neutrons and the element still maintains its identity

8. Questions 1) What particles make up an atom?
2) What are the charges on these particles?
3) What particles make up the nucleus?

9. Questions 1) What is Oxygen’s atomic number?
2) How many protons does Oxygen have?
3) If I have 4 protons what element am I?
4) If I have 4 neutrons what element am I?

10. Reading the Periodic Table
Mass

11. Atomic Mass Definition: the ~ mass of one atom of an element
Tells us how much one atom weighs in atomic mass units.
Mass

12. Organization of The Periodic Table
Group/Family
Period
Ordered by atomic mass. Columns arranged to form groups with similar properties

13. Assessment Which element has the greatest atomic mass? Lithium Sodium
Potassium
Rubidium
Rubidium

14. Reactivity
The ease and speed with which an element combines, or reacts, with other elements or compounds
Pure sodium reacts explosively
with air

15. Groups/families of elements have similar reactivity
Group 1: metals that react violently with water
Group 18: Gases that barely react at all

16. Atoms have neutral charge
# of Protons (+) = # of Electrons (-) = 0 charge
Example: Hydrogen
How many electrons does C have?
carbon has 6 electrons.

17. Take home message
The properties of an element can be predicted from its location on the Periodic Table

18. Metals, Metalloids, and Nonmetals

19. Metals Shiny Solids (at room temp) Malleable – can be hammered flat
Ductile – can be pulled into wire
High Conductivity – ability to transfer heat or electricity to another object

20. Reactivity of Metals Low High
Metals will usually lose electrons when they react with other elements

21. Nonmetals Sulfur Opposite of properties of metals Not shiny
Poor conductors
Mostly gases (at room temperature)
Solids are brittle
Sulfur

22. Reactivity of Nonmetals
Low
Low
High
Nonmetals will usually gain or share electrons when they react with other elements

23. Some Important Nonmetals
Carbon – important element for making up living organisms
Noble Gases – group 18 – very nonreactive. Have full outer shells.

24. Metalloids Inbetween metals and nonmetals Solids (at room temp)
brittle and hard
Semiconductors – can conduct electricity under some conditions but not others.
very important for computer chips
Most common example – Silicon – in sand and glass

25. Assessment The atomic number is the number of valence electrons.
neutrons.
protons in the nucleus.
electrons in the nucleus.
Protons in nucleus

26. Assessment
The periodic table is a chart of the elements that shows the repeating pattern of their
energies.
properties.
element symbols.
names.
properties

27. Assessment
Which piece of information cannot be found in a square on the periodic table?
Atomic mass.
Chemical symbol.
Atomic number.
Number of neutrons.
Number of neutrons

28. Assessment
Which side of the periodic table contains most of the nonmetals?
Left side.
Right side.
Middle.
Magnesium.

29. Assessment Which is not a property of nonmetals? Brittle.
Nonmalleable.
High conductivity.
Most are gases at room temperature
Magnesium.