1. Daily Science Sept 28
Grab a piece of construction paper and make a new unit tab over pages 30 and 31. The new unit is:
ATOMS AND THE PERIODIC TABLE
If you want to, draw a line on your table of contents under pages 21 & 22 and pages 29 & 30. That separates the units on your table of contents.

2. Anchor Phenomenon https://www.youtube.com/watch?v=3wxWNAM8Cso
We will use this phenomenon throughout our atoms unit

3. The Atom
Pg. 31

4. Early Theories There was no experimentation
Democritus- atoms are solid, homogeneous, indestructible, and indivisible
Aristotle- believed everything was made of either fire, water, earth, or air.
John Dalton- all matter composed of atoms; all atoms of one element are identical; atoms can’t be created or destroyed (actually used experiments)

5. Evolution of the Atomic Theory
The electron- discovered by JJ Thomson using a cathode ray tube; Robert Millikan discovered the negative charge
JJ Thomson came up with the plum pudding model. An atom was a mass ( pudding) with electrons scattered throughout (plums)
Ernest Rutherford discovered the nucleus using the gold foil experiment; said atom is mostly empty space with dense positive nucleus in the middle

7. Evolution of the atomic theory
Rutherford did more experiments and concluded the proton was in the nucleus
James Chadwick- discovered a neutral particle in the nucleus called the neutron
Atom- smallest particle of an element that still retains that elements properties

8. What do all the numbers mean?

9. Atomic Number
The atomic number of an element (labeled Z) tells you how many protons there are.
On the periodic table, the elements are listed as neutral elements so the number of electrons=the number of protons. Z

10. Calculating # of neutrons
The mass number (labeled A) is the number of neutrons + protons.
Mass number=atomic mass rounded to the nearest whole number
You can find the number of neutron by subtracting the Atomic number (Z) from the Mass number (A)
A-Z = # of neutrons

11. Abbreviations
Proton: p+
Neutron: no
Electron: e-

12. Shorthand notation
There is a way to represent atomic number and mass number
Steps:
1-start with the element symbol
2- place the mass number on the top left side of the symbol
3-place the atomic number on the bottom left side of the symbol

13. Al 27 13

14. https://play. kahoot. it/#/lobby