1. DEMOCRITUS
Greek philosopher that first used the term Atom meaning indivisible Stated that everything was made of Atoms. That atoms were solid and Between atoms was empty space.

2. DALTON
1803 John Dalton Atoms are tiny indestructible particles with no internal structure

3. Thomson’s Atomic Model
1897 J.J. Thompson Discovered the electron Electrons were Like plums Embedded in a positively Charged pudding

4. The Rutherford Atomic Model - 1911
4.2
The Atomic Nucleus
The Rutherford Atomic Model
Rutherford concluded that the atom is mostly empty space. All the positive charge and almost all of the mass are concentrated in a small region called the nucleus.
The nucleus is the tiny central core of an atom and is composed of protons and neutrons.

5. BOHR
Model consisted of a small positively- charged nucleus orbited by negatively charged electrons. Planetary model

6. Electron cloud model Most current model, describes where
Electrons are probably found

7. Early Models of the Atom
4.1
Early Models of the Atom
Early Models of the Atom
An atom is the smallest particle of an element that retains its identity in a chemical reaction.
an-atom
Philosophers and scientists have proposed many ideas on the structure of atoms.

8. Subatomic Particles What are three kinds of subatomic particles?
4.2
Subatomic Particles
Subatomic Particles
What are three kinds of subatomic particles?
Three kinds of subatomic particles are electrons, protons, and neutrons.

9. 4.2
The Atomic Nucleus
In the nuclear atom, the protons and neutrons are located in the nucleus. The electrons are distributed around the nucleus and occupy almost all the volume of the atom.

10. Distinguishing Among Atoms
The periodic table tells us information about the atoms of elements and their subatomic particles
Atomic Number = Number of protons
Electrons must equal protons = neutral atom (exceptions)
Mass Number = Number of protons + neutrons
Shorthand Notation: atomic # = subscript
Atomic mass= superscript

11. ISOTOPES
Isotopes: Atoms that have the same number or protons but different a different number of neutrons. Have different atomic mass numbers Behave alike since protons and electrons are the same

12. Atomic Mass
Atomic Mass; weighted average mass of the atoms in a naturally occurring sample of the element. includes isotopes (occur in nature) Why atomic mass is not a whole number

13. USES OF ISOTOPES Cobalt-60 used to irradiate food, destroys bacteria Iodine – 131 treats thyroid cancer Carbon – 14 Biological tracers (determine age of something) Americium-241 used in smoke detectors

14. 2. For the isotope Copper-63 What does the 63 stand for?
Atomic Structure Quiz
What does the subscript and superscript
tell you about chlorine. Be very Specific.
2. For the isotope Copper-63 What does the 63 stand for?
a.number of protons
b.number of neutrons
c.number of electrons
d.mass number
3. For the element magnesium (Mg) How many protons, neutrons, and electrons are there?