1. Name the steps of the scientific method in order
February 15 Bellwork
Name the steps of the scientific method in order

2. What is an Atom?
The smallest particle of matter that still has all of the properties and characteristics of that type of matter.
A copper atom is the smallest particle of copper that still has all properties of copper.

3. Brownian motion – the perpetual movement of particles (jiggling atoms) named after Robert Brown (Scottish Botanist)
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4. What Do Atoms Look Like?
An atom is mostly empty space and contains what we call subatomic particles. They are electrons, protons and neutrons.

5. Subatomic Particles
Protons with a positive charge found in the nucleus of an atom
Neutrons with a neutral charge also found in the nucleus of an atom
Electrons with a negative charge found outside of the nucleus in the electron cloud

7. The Periodic Table
The elements are arranged according to characteristics in a grid-like structure, both how they look as well as the way they act
Each box represents an element and each box contains the
Atomic number (number of protons/electrons)
Atomic mass number
Chemical symbol

8. Atomic Number The smaller number with no decimals
Represents the number of protons and electrons in a neutral atom
Periodic trend: increases from top to bottom and from left to right
Example: If the atomic number is 2, then the atom has 2 electrons and 2 protons.
Example 2: K has _19_ protons and _19_ electrons when neutral

9. Atomic Mass Number The larger number with a decimal
Measured in amu (atomic mass units)
Represents the number of protons and neutrons in an atom
Atomic Mass # = protons + neutrons

10. Therefore… To find the number of neutrons:
Neutrons = mass number – atomic number

11. Example Carbon has a mass number of 12.011 and an atomic number of 6.
How many protons does it have?

12. Chemical Symbol Single letters or first letter capitalized
If there are 3 letters, it is a man-made element that may get renamed
Gold – Au (aurum)
Iron – Fe (ferrum)

13. Any element with an atomic number greater than 92 is man- made

14. Isotopes
Atoms of the same element with the same number of protons but different number of neutrons
The mass number is an estimate of all of the possible isotopes of each element
Isotopes are the reason that there is usually a decimal point in the atomic mass number

15. Example of an Isotope C-12 has 6 neutrons, C-14 has 8 neutrons
C-12 is more often found in nature, so the atomic mass of C is which is closer to 12 than 14

16. How the Periodic Table is Set up
Metals, Nonmetals, Metalloids
Families (rows) and Periods (columns)

17. Metals
Located to the left of the zigzag (except hydrogen and metalloids)
Properties:
Luster (shine)
Can be stretched and shaped
Good conductors of heat/electricity

19. Nonmetals Located to the right of the zigzag Properties: Dull
Poor conductors of heat/electricity

21. Metalloids/Semi-metals/Semi-conductors
Along the zigzag: B, Si, Ge, As, Te, Po
Properties:
Some are shiny but some are dull
Not as good of conductors as metals but better than nonmetals

23. Periods (Rows) and Families (Columns)
Rows/Periods
Horizontal
Elements in the same period don’t have the same properties
7 on the periodic table

24. Periods (Rows) and Families (Columns)
Columns/Families
Also called groups
Vertical
Elements in the same group/family have common properties
18 on the periodic table

25. Li, Na, K all have a similar chemical reaction with water (H2O)
They all create an explosion that releases hydrogen gas (H2)
Therefore, they are stored with oil, not water.

26. Valence Electrons
The number of electrons in an atom’s outermost energy level
Elements in the same group/family have the same number of valence electrons

27. Atoms want to achieve a filled outermost energy level
we call this an “octet” if the energy level contains 8 valence electrons

28. Each Family of Elements Has its Own Name
Alkali Metals
Alkaline Earth Metals
Transition Metals
Halogens
Noble Gases

29. Alkali Metals Group 1 elements (except H) Have 1 valence electron
Are the most active metals
Tend to react with group 7 elements (halogens)

30. Alkaline Earth Metals Group 2 elements Have 2 valence electrons
Less reactive than alkali metals but still reactive
Tend to react with group 6

31. Transition Metals Groups 3-12 on periodic table
Metals, but different from alkali
or alkaline earth metals
Most have 1 or 2 valence e-s
Include mercury (Hg) – the only
liquid metal at room temperature

32. Halogens Group 7 elements
Some are gas, Br is liquid, and some are solid
Have 7 valence e-s
Tend to react with group 1 elements (alkali metals)

33. Noble Gases Group 8 elements Helium has 2 valence e-s
Ne, Ar, Kr, Xe, Rn, all have 8 valence e-s
Are not reactive since they already achieved an octet
Make up less than 1% of earth’s atmosphere
Oxygen (21%), nitrogen (78%) contribute to most of the atmosphere

34. Rare-Earth Elements
Includes elements at bottom of periodic table (periods 6&7)
First row = lanthanoid series (tend to be metals)
Second row = actinoid series (most are man- made and radioactive)

36. Names and Symbols of Commonly Used Elements
Aluminum (Al)
Boron (B)
Calcium (Ca)
Carbon ( C )
Chlorine (Cl)
Copper (Cu)
Helium (He)
Hydrogen (H)
Iron (Fe)
Nitrogen (N)
Oxygen (O)
Sodium (Na)
Gold (Au)

37. We Can Use the Periodic Table to Draw Bohr Models
A.k.a “planetary models”
Protons, neutrons and electrons are represented in the Bohr Model
We know that protons and neutrons are located in the nucleus at the center
The electrons are located in the electron cloud in energy levels

38. Energy Levels 1st level holds a max of 2 e-
2nd level holds a max of 8 e-
3rd level also holds 18 e-

39. Lewis (Dot) Diagrams
Electron dot diagrams are structures that show the valence electrons as dots
Valence electrons are the electrons in the outermost shell and can be determined by looking at the group number on the periodic table
Groups 1A – 8A (SKIP TRANS. METALS)

40. If an element is in group 1A it has 1 V. E
If an element is in group 1A it has 1 V.E. If an element is in group 5A is has 5 V.E.

41. Drawing Lewis Diagrams
To draw the diagram:
Write the symbol down
Place dots around the symbol, one on each side and then begin to pair them