1. Atoms, Elements, and the Periodic Table
Chapter 3
Atoms, Elements, and the Periodic Table

2. Important Vocabulary Matter Atom Law of Conservation of Matter
Electron
Nucleus
Proton
Neutron
Element
Atomic Number
Isotope
Mass Number
Atomic Mass
Metal
Non-Metal
Metalloid
Substance
Compound
Mixture

3. Launch Lab Get into your Science Teams
Look at the materials provided as I give you directions
Question: Will you see all three states of matter in this lab activity
Write your hypothesis
Perform the Experiment

4. Launch Lab Discussion What happened to the paper towel?
What caused this result?
Conclusion:
Water was the liquid state of matter
The paper towel was a solid
The air in the cup was the gas
Air is matter because it occupies space

5. What is matter?
Look at figure 1 on page 72. What in these pictures is matter?
Matter is anything that has mass and takes up space
Name some things that are not made up of matter.

6. Atoms A small particle that makes up most matter
In your science journal, draw what you think and atom looks like
At one time was believed to be a solid unit
Now broken into even smaller particles
Neutron, electron, and proton

7. Democritus Greek philosopher, lived from 460BC to 370 BC
Claimed that each type of matter was made up of specific atoms
For example: solid water (ice) is made of different atoms than liquid water
His ideas were ignored until the early 1800s

8. Lavoisier’s Contribution
French chemist, lived 2000 years after Democritus
Law of Conservation of Matter- Matter is neither created nor destroyed. It simply changes form
When you burn wood, what happens to the log?

9. John Dalton
Stated that matter is made up of atoms that are too small to be seen
Claimed that each element was made up of specific atoms that were unique to that element
His findings are known as the atomic theory of matter

10. JJ Thomson
Observed that electricity flowed from negative to positive components of a sealed tube and could be bent by a magnet
He knew that opposites attract and the beam was traveling towards a positive charge, so therefore the beam must be made of negatively charged particles
Electrons- subatomic particles with a negative charge

11. So what keeps us from being electrocuted?
You don’t get a shock when you touch everything, so what must also be present in the atom?
A positively charged particle
The proton

12. Ernest Rutherford
In 1910, his team shot gold foil with alpha particles
Positively charged particles
Since all of the alpha particles did not pass through the foil, he predicted that most of the atom was made up of empty space
Rutherford’s results provided him with information to name the nucleus
Nucleus- Positively charged central part of the atom
Contains protons

13. James Chadwick Assistant to Rutherford
Discovered the neutron- neutral particle in the nucleus
Found this data when he noticed that the gold atoms in the foil had released some mass with no charge
That unknown mass is what Chadwick called the neutron

14. Modern Atomic Model Look at Figure 8 on pg. 78
This model is the accepted atomic model (Bohr’s Model)
Notice the negatively charged electron cloud and the positively charged nucleus

15. New Research Modern science has advanced atomic research
Protons and electrons have whole charges +1 or -1
The particles in the nucleus are now broken down into even smaller particles called quarks
These particles are identified by their spin pattern and have a fractional charge
Up, down, strange, charmed, top, and bottom

16. The Simplest Matter Element- matter made up of only one kind of atom
At least 115 elements are known and 90 of them occur naturally on Earth
Non-natural elements are known as synthetic elements
Formed from nuclear reactions in machines known as particle accelerators

17. Organizing the Elements
Dmitri Mendeleev organized the first periodic table in order of each element’s mass
His table only included 60 known elements
The modern Periodic Table is organized by atomic number

18. Structure and Organization of
The Periodic Table
Structure and Organization of

19. Important Vocabulary Matter Atom Law of Conservation of Matter
Electron
Nucleus
Proton
Neutron
Element
Atomic Number
Isotope
Mass Number
Atomic Mass
Metal
Non-Metal
Metalloid
Substance
Compound
Mixture

20. What is an Atom? An atom is the simplest form of matter
It is made of three major particles
The Proton –
Positive Charge, In the Nucleus
The Electron –
Negative Charge, In the Shells and Orbitals
The Neutron -
No Charge, In the Nucleus

21. Let’s Draw an Atom - - + + + -

22. Notice a few things about our atom…
How many protons does it have?
How many neutrons does it have?
How many electrons does it have?
What is the object in the center?
How many rings does it have?
How many electrons are on the outside ring?

23. What do protons mean?
The number of protons is also the atomic number of the atom/element
Example: Hydrogen, atomic symbol H, has 1 proton since it is element #1
How many protons does each of these have?
Beryllium, Oxygen, Nitrogen, Xenon, Carbon
Name the element with the number of protons shown.
14, 27, 5, 30

24. What do Neutrons mean?
If you add the number of neutrons and protons, you get the atomic mass
This is the decimal number underneath the atomic symbol
Example:
Magnesium is element #12
How many protons?
Its atomic mass is , which rounds to 24.
How many neutrons does Magnesium have?

25. What do electrons mean?
Electrons are the negatively charged particles located in the rings around the nucleus
There are exactly the same number of protons as there are neutrons
How many electrons:
Sodium – Atomic Number 11
Silicon – Atomic Number 14
Arsenic – Atomic Number 33

26. What is the thing in the center?
That is the nucleus
Review:
What two particles are in the nucleus?
What overall charge does the nucleus have?

27. What do the rings mean?
The number of rings tells you on which row the element is located
Hydrogen has how many rings?
How many rings does Helium have?
What about Carbon?
What about Iodine?

28. What do the outer electrons mean?
The outer ring electrons are called valence electrons
These tell you to which column or family the element belongs
Special Note: This only applies to families 1,2 and 13-18
How many valence electrons does Hydrogen have? Neon? Aluminum?
Now for Rules on Rings…

29. Ring Rules The inner ring, #1, can only have 2 electrons
The second ring can have up to 8 electrons
The third ring can have up to 18 electrons
The fourth ring can have up to 32 electrons
All rings up to ring #7, the last ring, can have up to 32 electrons
KEY VOCAB: Energy Level – the rings containing electrons are actually called energy levels

30. 1 8 2 1 3 4 5 6 7 2
Transition Metals DO NOT Follow Rules 3 4 5 6 7

31. Naming the Elemental Families
Noble Gases
Alkali
Alkaline Earth
Naming the Elemental Families
Halogens
Transition Metals

32. Organization on the Periodic Table
Rows are called families
Have the same number of energy levels
Columns are called groups
Have the same number of valence electrons and bond similarly

33. Isotopes What do you know about isotopes?
Atoms with the same number of protons, but different numbers of neutrons
Isotopes determined by mass number (the sum of protons and neutrons in the nucleus)
Mass number on the periodic table is the average mass of the element

34. Hydrogen Isotopes Hydrogen has three isotopes Protium Deuterium
1 proton, 0 neutrons
Most abundant
Deuterium
1 proton, 1 neutron
radioactive
Tritium
1 proton, 2 neutrons

35. Element categories
Metals- shiny, metallic luster, good conductors of electricity and heat
All metals are solid at room temperature except mercury (liquid)
Non-metals- usually dull in appearance, brittle (can change shape)– be familiar with figure 17
Usually poor conductors of electricity
Many are gasses at room temp
Metalloids- characteristics of metals and nonmetals, found in a stairstep pattern between metals and non-metals
All are solid at room temp

36. Metalloid Stairstep

37. Compounds and Mixtures
Substance- mixture with the same chemical properties throughout
Compound- substance whose smallest unit is made up of atoms of two or more elements
Have properties different than the elements that make up the compound

38. Compound Example What are some properties of hydrogen?
What are some properties of oxygen?
What are some properties of the compound made up of 2 hydrogen atoms and 1 oxygen atom?
What about 2 hydrogen and 2 oxygen?

39. Compounds Have formulas Naming the formulas
Prefixes: mono-, di-, tri-, quad-, pent- hex-, hepto-, octo-, nono- deca-
Suffixes: -ine, -ane, -ite, -ate, -ous
Let’s practice a few naming problems

40. Name these: Sodium (Na) + Chlorine (Cl) = NaCl
Hydrogen (H) + Oxygen (O) = H2O
Hydrogen (H) + Chlorine (Cl) = HCl
Carbon (C) + Oxygen (O) = CO2
8 Hydrogen (H) + 3 Carbon (C) = H8C3
Hydrocarbons have special naming techniques- we will discuss these techniques in Chapter 9

41. Mixtures
When two substances (elements or compounds) do not combine to make a new substance when mixed
What happens when you combine oil and water?
Observe the bottle I have prepared.

42. Two kinds of Mixtures Homogeneous- the same throughout
Examples: Teas, Soda, Fruit flavored soft drinks
Heterogeneous- larger components that are visibly different from one another
Examples: Salads, cookies, mixed nuts

43. A Quick Review Describe and name the parts of an atom
Name 5 things that are matter and five things that are not matter
What is the difference between atomic mass and atomic number?
Name and describe the Isotopes of Hydrogen

44. A quick Review What is an isotope and what makes them possible?
Solve: An atom of Phosphorous has 15 protons and 15 neutrons, what is the mass number?
Solve: The element Tungsten has a mass number of 184, how many neutrons does Tungsten have?

45. A Quick Review
What is the difference between homogeneous and heterogeneous mixtures?
What three types of elements are there and give properties of those elements?