1. WARM-UP
What do all these pictures have in
common with each other?

2. What is an Atom?
ACHS Physical Science

3. Objective/Concept Question
I will develop a model that differentiates atoms and molecules by diagramming the configuration of a mystery atom.
“What is all my stuff made of?”

4. MINI-LESSON History of the ATOM These will be 2-Column (Cornell Notes)
Words in BLUE will go in the LEFT column (headings)
Words that are UNDERLINED you will write in the RIGHT column

5. Scientists who discovered Atomic Structure
Democritus – (460BC)
postulated that everything was made of “ATOMAS” which were physically divisible but had different shapes (Salt atoms were pointy

6. Scientists who discovered Atomic Structure
Rutherford – (1910) Experimented by firing Helium atoms at Gold foil and found that most passed through but 1 in 10,000 would ricochet off.
Bohr – (1913) refined Rutherford’s idea of the Atom saying the electrons were in ORBIT around a central nucleus

7. Rutherford’s Experiment
gold foil
helium nuclei
helium nuclei
They found that while most of the helium nuclei passed through the foil, a small number were deflected and, to their surprise, some helium nuclei bounced straight back.

8. Bohr’s Atom
electrons in orbits
nucleus

9. Question….
WHERE DO WE FIND ATOMS?????

10. What is an Atom?
Atoms are the basic building blocks of matter that make up everyday objects (your desk, the air, even YOU are made up of atoms!)
There are 90 naturally occurring kinds of atoms. Scientists in labs have been able to make about 25 more

11. What is an Atom? Atoms are made out of 3 basic particles:
PROTONS– carry a positive charge
NEUTRONS– carry no charge
Protons and Neutrons join together to form the Nucleus of the atom
ELECTRONS – carry a negative charge and circle the nucleus

12. Practice!
Proton
Neutron
Electron

13. What is an Atom? Neutrons and protons have almost the same mass
If an electron weighed the same as a dime—a proton would weigh the same as a gallon of milk!

16. Atomic Structure – Helium Atom
Shell
proton N + - + N -
neutron
electron

17. Atomic Structure - Helium
Atomic Mass refers to the “weight” of the atom.
It is derived at by adding the number of protons with the number of neutrons.
This is a helium atom. Its atomic mass is 4 (protons plus neutrons).
What is its atomic number?

18. number of electrons = number of protons
ATOMIC STRUCTURE He 2
Atomic number
the number of protons in an atom 4
Atomic mass
the number of protons and
neutrons in an atom
number of electrons = number of protons

19. ATOMIC STRUCTURE Practice! number of electrons = number of protons8
Atomic number
the number of protons in an atom 16
Atomic mass
the number of protons and
neutrons in an atom
number of electrons = number of protons

20. ATOMIC STRUCTURE Practice!Cu 29
Atomic number
the number of protons in an atom 63
Atomic mass
the number of protons and
neutrons in an atom
number of electrons?

21. ATOMIC STRUCTURE Practice!Na 11
Atomic number
the number of protons in an atom 22
Atomic mass
the number of protons and
neutrons in an atom
number of electrons?

22. ATOMIC STRUCTURE Practice!6
Atomic number
the number of protons in an atom 12
Atomic mass
the number of protons and
neutrons in an atom
number of electrons?

23. Atomic Structure Adding a proton makes a new kind of atom
What is an ISOTOPE?
Adding a neutron makes an isotope of that atom – just a heavier version of that atom

24. Atomic Structure
The last energy level consists of what’s called VALENCE ELECTRONS
These are the electrons that will make the bond with other elements
Electrons occupy different Energy “LEVELS” within an atom.
The first energy level holds 2 electrons
The remaining energy levels all hold 8 electrons

25. Atoms vs. Elements vs. Molecules
Imagine going to an ice cream store. Let’s say they have 30 different flavors of ice cream.
Those are ELEMENTS, the things that I have available to build my dessert from.
The smallest amount of ice cream that the store will sell to me is a scoop. This is an ATOM.
If I want, I can put 2 or more scoops of ice cream together. This is a MOLECULE
If my molecule has more than one flavor of ice cream, I can call it a COMPOUND

26. Atoms vs. Elements vs. Molecules
IN SUMMARY:
Element: a basic substance that can’t be simplified
Atom: the smallest amount of an element
Molecule: two or more atoms that are chemically joined together (H2, O2, H2O etc…)

27. Today you are going to BUILD a model of an ATOM!!
Time to Practice
Today you are going to BUILD a model of an ATOM!!
In your group you will be responsible for:
Choosing an Atom
Deciding how to represent each of the parts (PNEs)
Creating a “Get to know an Atom” Information card

28. REFLECTION – Mystery Atom!
You are going to get a card with a mystery atom’s information on it.
You will need to create an INFORMATION CARD for your mystery atom given either the number of PROTONS or NEUTRONS and the ATOMIC MASS!

29. ACCESS! 6-Trait Writing criteria – what are they?
Today in Access we are going to complete several Short Constructed Responses.
Pick 2 questions to answer
Answer the questions on the back of the page (make sure to write which questions you are answering!)