Transcript of The Periodic Table – Chapter 7 By Mrs. Shaw. What is the Periodic Table? The Periodic Table is a...
- Slide 1
- The Periodic Table Chapter 7 By Mrs. Shaw
- Slide 2
- What is the Periodic Table? The Periodic Table is a chart of
the elements arranged into rows and columns according to their
physical and chemical properties. Columns = Groups Rows = Periods
Lesson 1: Using the Periodic Table
- Slide 3
- The Development of the Periodic Table The Periodic table of
elements was devised to organize the known elements into categories
that had similar properties. Dimitri Mendeleev, a Russian chemist,
decided to organize the elements in order by atomic mass. When he
did that he noticed a repeating pattern appeared of elements with
similar properties. Periodic means repeating pattern.
- Slide 4
- Mendeleevs original periodic table Notice the gaps that he
allowed for.
- Slide 5
- New discoveries led to new table In 1914 Henry Moseley, a
British scientist, determined that rearranging the elements in
order of their atomic number actually worked to align the elements
based on their similar physical and chemical properties and filled
in all the newly discovered elements. Atomic number = # of protons
Element Symbol Element Name Atomic mass (average )
- Slide 6
- Periods Groups or Families Arranging the Elements A vertical
column of elements is called a group or family. Elements in each
group or column usually have similar properties. Each row of
elements is called a period.
- Slide 7
- Periods (rows)-Arranged by increasing atomic weight Periods
have the same number of shells 1 2 3 4 5 6 7 Example:Period 1 = 1
shell Period 2 = 2 shells Period 3 = 3 shells
- Slide 8
- Groups- (columns) Arranged by the number of valence electrons
Each group has similar bonding properties Example:Group 1 =1
valence electron Group 2 =2 valence electrons Group 3 = 3 valence
electrons
- Slide 9
- Four chemical groups of the periodic table: 1. alkali metals
(IA) 2. alkaline earth metals (IIA), 3. Halogens (VII), 4. Noble
gases (VIIIA).
- Slide 10
- Slide 11
- Classification of the Elements Elements in the periodic table
are classified into three main groups: metals, nonmetals, and
metalloids.
- Slide 12
- Metals! Over 70% of elements are metals Metals
- Slide 13
- What are the physical properties of metals? Metals are elements
that are: shiny ductile-easily pulled into wires malleable-hammered
into thin sheets good conductors of electricity and thermal energy.
Malleable Shiny (have luster) Good conductivity Ductile
- Slide 14
- Other physical properties of metals Density, boiling point, and
melting points are greater in metals than of other types of
elements. AND Except for Mercury all metals are SOLID at room
temperature.
- Slide 15
- Properties Examples Remember elements in the same group
(column) have similar properties. Alkali metals are very reactive
(they want to chemically bond so are found in compounds) Pure
alkali metals are silvery and soft enough to cut with a knife and
have the lowest densities of all metals. Group 1: Alkali Metals K +
H2O Na Group 1
- Slide 16
- Examples Properties React quickly but not as quick as alkali
metals. Found as compounds due to their need to react. Soft,
silvery with low densities but not as low as alkali metals. Group
2: Alkaline Earth Metals Mg
- Slide 17
- Groups 3-12: Transition Metals Transition metals have higher
densities, boiling points and greater strength than other types of
metals (alkali or alkaline earth). They react less than other
metals and some exist as free elements (not as a compound).
Examples are: Nickel (Ni), Copper (Cu) and Gold (Au)
- Slide 18
- Nonmetals Nonmetals include the Noble gases. Nonmetals
- Slide 19
- Properties of Nonmetals Non-metals are brittle, dull, and not
good conductors of thermal or electrical energy. Because they are
not good conductors they are really good INSULATORS! Many are gases
at room temperature.
- Slide 20
- Examples of Insulators The nose cone on the tip of the space
shuttles are created using non-metals that insulate against the
intense heat of re-entry! Other examples
- Slide 21
- Lesson 3: Nonmetals and Metalloids Did you know that more than
96% of your bodys mass comes from just 4 elements Oxygen, Carbon,
Hydrogen, and Nitrogen and all are Nonmetals.
- Slide 22
- Metalloids Metalloids have some of the properties of metals and
some of the properties of nonmetals. Metalloids
- Slide 23
- Properties of Metalloids Metalloids are elements that have
properties of both metals and nonmetals. Some metalloids are
semiconductors or an element that conducts electricity at a high
temperature but not a low temperature
- Slide 24
- Lanthanide & Actinide Series Lanthanide series elements are
used to make strong magnets. Plutonium is an element in the
actinide series that is used as fuel in some nuclear reactors.
- Slide 25
- Pattern in properties of metals Metallic properties increase as
you move to the left and down on the periodic table.
- Slide 26
- Slide 27
- Valence Electrons Valence electrons are the electrons in the
outermost shell that determines a atoms chemical properties. The
amount of electrons in the outer level determine if an atom will
likely bond with another they want to be full so bonding will help
that happen.
- Slide 28
- Chemical bonding Chemical bonding is the joining of atoms to
form new substances. A chemical bond is an interaction that holds
two atoms together. Most atoms form bonds by gaining, losing, or
sharing valence electrons until they fill their outer shell to
become happy.
- Slide 29
- Types of Chemical Bonds There are two types of chemical bonds
we will discuss: ionic bonds and covalent bonds.
- Slide 30
- Ionic Bonds Ionic bonds happen when electrons are transferred
from one atom to another, causing the atom to become either
positively charged or negatively charged. Na + Cl = Na Cl Table
Salt
- Slide 31
- Ionic Bond
- Slide 32
- Covalent Bonds Covalent bonds happen when atoms share
electrons. For example: Chlorine needs one electron to have a full
outer shell so it can share 2 electrons with another Chlorine atom
and become stable.
- Slide 33
- Covalent Bonds Another very important covalent bond is H + H +
O = H2O