1. 7B16 Periodic Table Elements

2. Vocabulary
Element: substance that cannot be broken down into other simpler substances.
There are ~90 natural elements and 25 man-made
Atom: smallest particle of an element, each very different from one element to another.
Atomic Number = protons, and place in table
Atomic Mass = how much mass the atom has
React: when elements combine chemically
Compound: substances with 2 or more types of atoms held together by bonds.
Periodic: repeating regularly

3. H = Hydrogen = Atomic Number 1
Hydrogen is very light weight but flammable.

4. Background
2000 years ago Greeks thought everything was made from elements: fire, earth, air and water
In the 1600’s chemists realized those were not elements like carbon, gold, silver, copper, lead, tin, sulfur, mercury, and iron, all found in nature. The rest were discovered later.
But what did they have in common with each other?

5. Dmitri Mendeleev
Russian scientist who developed the modern Periodic Table with 63 known elements (1869)
Collected information on element properties.
Grouped elements by their:
Atomic mass
Physical and Chemical properties
He noticed a periodic pattern
(periodic means repeating)

6. First Periodic Table
The 63 elements he knew were NOT the first 63 in the Periodic Table. Some were missing!
He put elements into similar groups and left some blanks in the table where he predicted that new elements would be found and placed
He even used the patterns in the table to predict the properties of the new elements.
Later scientists proved he was right!

7. Mendeleev’s Table

8. Modern Periodic Table

9. Modern Periodic Table of Elements
Everything is made from only 115 elements.
Each element represented by a symbol, either
One uppercase letter, like C for carbon, or
An uppercase and lowercase, like Cu for copper

10. Families or Groups There are several other pieces of information.
There are several “families” or groups:
Non-metals
Alkali metals
Alkaline earth metals
Transition metals
Rare earth metals
Other metals
Halogens
Noble gases

11. Label Your Periodic Table
Label the groups (columns) as 1-18 at the top.
Label the periods (rows) as 1-7 down the left.
Using a dark color, draw a zig-zag diagonal staircase line dividing metals from non-metals.
Left of B, between B & Al, between Al & Si, between Si & Ge, between Ge & As, between As & Sb, between Sb & Te, between Te & Po, between Po & At
Draw circles around Br (35), Hg (80), and UUB (112). These are liquids at room temperature.

12. Color Your Periodic Table
Draw & label a Color Key like p. B27 in your textbook.
Color each group with its designated color.

13. Challenge Question 1 Decide if each element is… a metal or non-metal.
(Li) lithium
(C) carbon
(S) sulfur
(Ca) calcium
(Ti) titanium
(Br) bromine
Metal
Non-metal

14. Solid, Liquid, or Gas
Most elements are solid at room temperature. Their symbols are shaded black.
The 11 elements that are gases tend to be at the top right corner of the table. Their symbols are shaded white.
3 elements are liquid at room temperature. Their symbols are shaded gray.

15. Reactivity React is when elements combine chemically.
Elements likely to combine are highly reactive, so they will react with many other substances.
The least reactive elements are the noble gases in the far right column.
The most reactive metals are in the two columns on the far left.
The most reactive non-metals are in the halogen family in column 17.

16. Challenge Question 2 Find magnesium on the… Periodic Table
What is magnesium’s chemical symbol?
Is magnesium a solid, liquid, or gas?
What family does magnesium belong to?
Based on its family, do you expect magnesium to be very reactive, not reactive, or somewhat reactive? Mg
Solid at room temperature
Alkaline earth metals
Very reactive

17. Forming Compounds Elements contain only one type of atom.
Compounds contain two or more types of atoms held together by chemical bonds.
Water forms when hydrogen and oxygen react
The 115 elements form millions of compounds
This is similar to how many words in the dictionary are formed from just 26 letters.
Compounds and their elements have different properties. H2O is different than elements H or O.

18. Chemical Names Compound names often identify the elements
Table salt is called “sodium chloride”, so its name says it contains sodium and chlorine. Notice the ending is changed from “chlorine” to “chloride” in the compound name.

19. Chemical Formulas
Chemical formulas are a short way to identify the kind and number of atoms in a compound.
Na=sodium, Cl=chlorine, so table salt formula is NaCl=sodium chloride
Water is made of two hydrogen atoms bonded to one oxygen atom.
H = hydrogen, O = oxygen, so water = H2O
The 2 means 2 hydrogens. No number means 1.

20. Challenge Question 3 The chemical formula for… baking soda is NaHCO3
What elements are in baking soda?
How many of each kind of atom is represented by the formula for baking soda?
Na=sodium, H=hydrogen, C=carbon, O=oxygen
One Na sodium, one H hydrogen, one C carbon, and three O oxygens

21. Classifying Matter
Everything around you is either an element, a compound, or a mixture of both.
Helium balloons & copper in pennies=elements
Water, salt, sugar, protein and fat=compounds
Air is a mixture since it contains elements like oxygen and nitrogen, and compounds like carbon dioxide and water.

22. 7B16 Periodic Table Analysis pB30
On another paper copy & explain in 1 paragraph 2) Sodium and chlorine form sodium chloride, or table salt. Is table salt an element or compound? 3) Is seawater an element, compound, or mixture? Give examples and explain. 4) Explain the relationship between an atom and a compound.