Atoms and Elements

1
Atoms and Elements
2
Development of Atomic Structure

• Dalton
• Franklin
• Thomson
• Becquerel
• Curie
• Rutherford
• Millikan
• Chadwick

3
Radioactivity

• 1896 Becquerel uranium ore emitted rays that
  caused photographic plates to darken as if
  exposed to light
• 1898 Curie Elements Radium and Polonium were
  isolated which also gave off the same type of
  rays. M Curie suggests that these rays emitted
  when atoms disintegrate (decay)
• phenomena called radioactivity.

Alpha a Helium nucleus (2 charge) Beta ß
high speed electron Gamma ? (high energy
electromagnetic radiation)
4
Radiation

• Alpha decay
• Beta decay
• Alpha and Gamma Decay

5
Modern Theory Atomic Structure

• Subatomic particles are?
• Nucleus is composed of?
• Electrons are in clouds. What does that mean?

http//www.phrenopolis.com/perspective/atom/index.
htmlelectron
6
Symbol
How many protons?
How many neutrons?
How many electrons?
7
Which of the following drawings represents an Na
atom? A Ca 2 ion? A F1- ion?
8
Be familiar with.

• Isotopes
• 3 isotopes of hydrogen
• Atomic Mass
• Atomic mass unit

9
Be familiar with

• Percent abundance
• Average atomic mass (atomic weight)
• Calculations involving abundance, atomic weight

10
Moles and Moles

• How many atoms in a mole?
• What does the mole do?
• How do you calculate molar mass?
• Be able to do calculations involving the mole

11

Periodic Table

• Period
• Group
• Metals
• Non-metals
• Semi-metals (metalloid)
• Alkali Metals
• Alkali Earth Metals
• Transition Metals

• Chalcogens
• Halogens
• Noble gases
• Lanthanides and Actinides
• Main group elements (representative elements)
• Diatomic elements

12
Diatomic Elements
13
Is the element marked in red on the following
periodic table likely to be a gas, a liquid, or a
solid? What is the atomic number of the element
in blue? Name at least one other element that is
chemically similar to the element in green.
14
The radioactive element indicated on the
following periodic table is used in smoke
detectors. Identify it, give its atomic number,
and tell what kind of group its in.
15
Development of periodic Table

• Mendeleev
• Moseley
• Periodicity
• Periodic repetition of the properties of elements
• Law of Chemical Periodicity
• Properties of the elements are periodic functions
  of atomic number

16
Overview of the Elements

• React with water
• React with water
• Al most abundant metal in Earths crust
• Carbon exists in several allotropes
• ¾ of atmosphere is nitrogen
• Oxygen is most abundant element in Earths crust
• Halogens are very reactive elements
• Helium 2nd most abundant element in universe
• All transition elements are metals

• Group 1A
• Group 2A
• Group 3A
• Group 4A
• Group 5A
• Group 6A
• Group 7A
• Group 8A
• Transition