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
Slide 3
H = Hydrogen = Atomic Number 1 Hydrogen is very light weight
but flammable.
Slide 4
Background 2000 years ago Greeks thought everything was made
from elements: fire, earth, air and water In the 1600s 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?
Slide 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)
Slide 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!
Slide 7
Mendeleevs Table
Slide 8
Modern Periodic Table
Slide 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
Slide 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
Slide 11
Label Your Periodic Table 1.Label the groups (columns) as 1-18
at the top. 2.Label the periods (rows) as 1-7 down the left.
3.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 4.Draw circles around Br (35), Hg (80), and UUB
(112). These are liquids at room temperature.
Slide 12
Color Your Periodic Table Draw & label a Color Key like p.
B27 in your textbook. Color each group with its designated
color.
Slide 13
Challenge Question 1 Decide if each element is 1.(Li) lithium
2.(C) carbon 3.(S) sulfur 4.(Ca) calcium 5.(Ti) titanium 6.(Br)
bromine a metal or non-metal. 1.Metal 2.Non-metal 3.Non-metal
4.Metal 5.Metal 6.Non-metal
Slide 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.
Slide 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.
Slide 16
Challenge Question 2 Find magnesium on the 1.What is magnesiums
chemical symbol? 2.Is magnesium a solid, liquid, or gas? 3.What
family does magnesium belong to? 4.Based on its family, do you
expect magnesium to be very reactive, not reactive, or somewhat
reactive? Periodic Table 1.Mg 2.Solid at room temperature
3.Alkaline earth metals 4.Very reactive
Slide 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. H 2 O is different
than elements H or O.
Slide 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.
Slide 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 = H 2 O The 2 means 2 hydrogens. No number means 1.
Slide 20
Challenge Question 3 The chemical formula for 1.What elements
are in baking soda? 2.How many of each kind of atom is represented
by the formula for baking soda? baking soda is NaHCO 3 1.Na=sodium,
H=hydrogen, C=carbon, O=oxygen 2.One Na sodium, one H hydrogen, one
C carbon, and three O oxygens
Slide 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.
Slide 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.