1. 1. Atom
The smallest particle of an element that still has the properties of that element

2. no electrical charge
positive charge
center of atom
negative charge

3. 2. Compound Made of combination of elements
Properties of compounds often differ from properties of elements that make them up

4. hydrogen= H
carbon= C +
C6H12O6
oxygen= O + =

5. 6 carbon atoms 12 hydrogen atoms 6 oxygen atoms
ex. C6H12O6 = glucose (sugar)
6 carbon atoms
12 hydrogen atoms
6 oxygen atoms

6. 3. Atomic Theory – the beginning
Democritus believed that the tiniest particle was the atom, which was the smallest thing that could ________________________________.
He also thought that atoms were made of a _________________________________ that formed into different shapes and sizes.
be divided to
single material
Atomos  indivisible

7. 4. John Dalton’s Atomic Theory
Based on scientific _________________________ through __________________, John Dalton published a theory in His theory states these ideas:
evidence
experiments

8. 4. John Dalton’s Atomic Theory
All substances are made of ________________. Atoms are small particles that cannot be ________________, __________________, or _________________________.
Atoms of the same element are ________________________________. and the atoms of different elements are ___________________________.
Atoms join with other atoms to make ______________________________.
atoms
created
divided
destroyed
exactly alike
different.
new substances

9. 5. Disagreeing with Dalton
As scientists were able to gather new data, more discoveries about the atom showed some mistakes with Dalton’s theory.
J. J. Thompson discovered with a __________________________ that atoms contained ___________________-charged particles called ___________________. He came up with the ______________________________ model.
cathode-ray
negatively
electrons.
Plum-pudding

10. 6. Rutherford’s Atomic Discoveries
Later, one of Thompson’s students named Ernest Rutherford discovered the ________________________-charged particles in the center of the atom. .
positively

11. 6. Rutherford’s Atomic Discoveries
Gold-foil
He designed the _____________________ experiment. .

13. 7. Bohr’s Model and Modern Theory
With more experiments and evidence, Niels Bohr developed his model named after himself, called the ________________ model. 
This model represents a small, positively-charged __________________ surrounded by _____________________ that travel in _________________________________ around the nucleus.
Bohr
nucleus
electrons
circular orbits

15. 7. Bohr’s Model and Modern Theory
Modern Theory developed by scientists, especially Schrödinger and Heisenberg, states that electrons are found in probable ______________________________ called __________________________________.
regions
Electron clouds

16. Now let’s draw the models that evolved throughout history.