1. What are they and what do they do?
6/3/2018
Atoms
What are they and what do they do?

2. What are atoms? Atoms are the smallest particles of matter
Atoms make up everything around us
Molecules are combinations of atoms
Elements are only one type of atom
Compounds are made up of different types of atoms
Hydrogen Gas
Water
Dan Kelly - Magic of Electrons - PLTW - Atoms

3. Atoms vs. Elements
What is the difference between atoms and elements? Atoms make up elements. To be an element, it can ONLY have ONE type of atom. The terms are often used interchangeably. For example, the Periodic Table of the Elements could also be written as the … Periodic Table of Different Types of Atoms.
Dan Kelly - Magic of Electrons - PLTW - Atoms

4. Let’s Recap What is an atom? What is an element? What is a molecule?
Atoms are the smallest particles of matter.
What is an element?
Elements are made up of only one type of atom.
What is a molecule?
Molecules are combinations of atoms.
What is a compound?
Compounds are made up of different types of atoms.
What are some examples of these?
Dan Kelly - Magic of Electrons - PLTW - Atoms

5. Components of an Atom Nucleus. Protons: (+) Neutrons:
6/3/2018
Components of an Atom
What makes up an atom?
At the center of all atoms is the
Nucleus.
The nucleus contains protons
and neutrons.
Protons: (+)
Positively charged atomic particles
Neutrons:
Uncharged (neutral) atomic particles
Demonstration on positive vs. negative
Dan Kelly - Magic of Electrons - PLTW - Atoms

6. Components of an Atom Electrons: (-) What makes up an atom?
6/3/2018
Components of an Atom
What makes up an atom?
Orbiting around the nucleus are the
electrons.
Electrons: (-)
Negatively charged atomic
particles
Nature prefers balance so if a
particle is positively charged, it
will attract negatively charged
particles and vice-versa.
Demonstration on positive vs. negative
Explain orbiting free-fall
Dan Kelly - Magic of Electrons - PLTW - Atoms

7. Components of an Atom Electrons: Protons: Neutrons: Recap
6/3/2018
Components of an Atom
Recap
Where would you find the following parts of an
atom and what is its charge?
Protons:
In the center of the atom
Positive charge
Neutrons:
Uncharged
Electrons:
Orbiting the atom
Negative charge
Demonstration on positive vs. negative
Explain orbiting free-fall
Dan Kelly - Magic of Electrons - PLTW - Atoms

8. Atomic Number How many protons are in this nucleus?
6/3/2018
Atomic Number
The atomic number is equal to the
number of protons in the nucleus
of an atom.
The atomic number identifies
the element.
How many protons are in
this nucleus?
(assume the protons are red)
Demonstration on positive vs. negative
Dan Kelly - Magic of Electrons - PLTW - Atoms

9. Matter Notes Five states of Matter
Phases of matter, mixtures and solutions.
Five states of Matter
Bose-Einstein condensate
solids liquids gases plasma

10. Changing states of matter
Elements and compounds can move from one phase to another phase when special physical forces are present.

11. Phase changes All matter can move from one state to another.
Energy makes the difference.
Freezing point is when a liquid turns into a solid.
Melting point is when a solid turns into a liquid.
Pressure can also make a difference.

12. Physical vs. Chemical Change
Physical changes are about energy and states of matter.
Chemical changes happen on a molecular level.
You can cause physical changes with forces like motion, temperature, and pressure.

13. Physical vs. Chemical Change
Chemical changes happen on a much smaller scale.
Melting a sugar cube is a physical change because the substance is still sugar.
Burning a sugar cube is a chemical change. The energy of the fire has broken down the chemical bonds.
The actual molecules have changed their structure

14. Solids Solid holds its shape.
The atoms still spin and the electrons fly around, but the entire atom will not change position.
More than one type of compound in a solid it is called a mixture.
Atoms arranged in a regular repeating pattern called a crystal lattice.

15. Liquids Fill the shape of their container.
Tops are flat because of gravity.
Difficult to compress.
Liquids have cohesive (sticky) forces at work that hold the molecules together.

16. Evaporation
Evaporation is all about the energy in individual molecules, not about the average energy of a system.
The average energy can be low and the evaporation still continues

17. Evaporation
The energy you can measure with a thermometer is really an average of all the molecules in the system.
There are always a few molecules with a lot of energy and some with barely any energy at all.
Examples:
Cold hands when wet,
Wet hair give you a cold.

18. Gas Gases can fill a container of any size or shape.
Gases are random groups of atoms.
Vapor and gas mean the same thing.
Can be compressed fairly easily.

19. Plasma Made up of free electrons and ions of the element.
Balanced charge.
Northern Lights or ball lightning
Examples:
Neon signs
Stars

20. Bose-Einstein Condensate
Two scientists, Satyendra Bose and Albert Einstein, predicted it in the 1920.
In 1995, two scientists, Cornell and Weiman, finally created this new state of matter.
They are super-unexcited and super-cold atoms.

21. Bose-Einstein Condensate
When you get to a temperature near absolute zero something special happens. Atoms begin to clump.
A group of atoms takes up the same place, creating a "super atom."

22. Mixtures vs Solutions vs Compounds

23. Mixtures
Combination of two or more substances that are not chemically combined
No new substance formed
Do not exist in fixed proportions to each other
They just mix
Most natural substances are mixtures
Can be physically separated into pure compounds or elements
Can be separated by mechanical means
Physical properties can change
Any combination of solid, liquid or gas can be a simple mixture

24. Solutions
Homogeneous is molecules that are mixed up in a completely even distribution
Heterogeneous is not
(Macaroni Salad)

25. Solutions A solute is the substance to be dissolved (sugar).
The solvent is the one doing the dissolving (water).
Can be solids in liquids, gases in liquids, or even two in same state.

26. How to make a Solution Solute=Sugar, Solvent=Water, System=Glass.
1. The solute is placed in the solvent and the concentrated solute slowly breaks into pieces.

27. How to make a Solution
2. The molecules of the solvent begin to move out of the way and they make room for the molecules of the solute. Example: The water has to make room for the sugar molecules.

28. How to make a Solution
3. The solute and solvent interact with each other until the concentration of the two substances is equal throughout the system. The concentration of sugar in the water would be the same from a sample at the top, bottom, or middle of the glass.

29. Solubility
Solubility is the ability of the solvent (water) to dissolve the solute (sugar).
Increase Temp: allows more solids and less gas.
Increase Pressure: more gas (think coke)
Molecular Structures: In water, sugar vs. oil. Oil has low solubility in water.

30. Mixtures
Mixture = substances held together by physical forces, not chemical
Distilled water, it's a pure substance. Salt water has something else in it that can be removed by physical forces. (boiling off the water)

31. Mixtures Solutions are also mixtures.
A solution can also be made of two liquids. Even something as simple as bleach and water is a solution.

32. Other types of Mixtures
Alloys are basically a mixture of two or more metals.
Metallurgists (people who work with metals) sometimes add chromium (Cr) and/or nickel (Ni) to steel. (Stainless Steel)

33. Other types of Mixtures
Amalgams are alloys that combine mercury and other metals.
Mercury as "quicksilver" or the metal that is liquid at room temperature.

34. Other types of Mixtures
Emulsions are Colloids that have a mixture of oils and waters
As time passes, the oil and water will separate to their original states. (Think salad dressing)