Physical Science – Chapter 19 Study Guide Answers
Chapter Objectives
1. Identify the names and symbols of common elements.
Be able to read and use your periodic table
2. Describe the electron cloud model of the atom.
Area around the nucleus where electrons are found, electrons are moving so fast cannot pinpoint their location
Current model of the atom
1st person to say that atoms were made of smaller particles…..DEMOCRITUS
3. Explain how electrons are arranged in an atom.
Around the nucleus, cannot say exactly where, no set pattern of movement
4. Compute the mass number of an atom.
Mass Number = number of protons and neutrons
Average atomic mass = average masses of all the isotopes
5. Identify the components of isotopes.
Same element (same number of protons) but a different number of neutrons, which results in a different mass
Most elements have more than 1 isotope
6. Explain the composition of the periodic table. (i.e. periods, groups)
Arrangement of elements by atomic number (number of protons)
Developed by Mendeleev and Moseley
Periods = rows
Groups/families = columns
1 – Alkali Metals
2 – Alkaline Earth metals
3-12 = transition Metals
17 = Halogens
18 = Noble gas
7. Use the periodic table to obtain information.
Data obtained from periodic table = atomic number (# of protons), mass number/average atomic mass, state at room temperature, metal/nonmetal/metalloid (semimetals), group or family, period, name and symbol
Staircase = metalloids/semi-metals
As you move across the periodic table from left to right, you add a proton and electron to the elements
8. Explain what metals, nonmetals and semi-metals are and where they are located on the periodic table.
Metals = left side of the PT, shiny, good conductors, solids, metallic
Non-metals = right side of the PT, most are gases, poor conductors, brittle
Semi-metals = staircase, properties of metals and nonmetals
Key Concepts
9. Characteristics of Protons, Neutrons, Electrons
Protons = positively charged, found in the nucleus, 1 amu
Neutrons = neutral/uncharged, found in the nucleus, 1 amu
Electrons = negatively charged, around the nucleus, hard to pinpoint, ridiculously small ~0 amu
10. Quarks
Make up protons and neutrons, 6 different quarks
11. Electron Dot Diagrams
Represents the bonding electrons/valence electrons available for the element
Each group has the same number of outer energy level electrons
12. Atomic Number
Tells you the number of protons for the element
Used to identify elements
Periodic table is arranged according to atomic number
13. CHEMICAL SYMBOL
Abbreviation of the name
First letter is capitalized, 2nd letter is lower case
Only 26 letters of the alphabet, but over 115 elements, some use more than 1 letter
14. Identifying period and group for an element
Period = rows
Group = columns
15. Use periodic table to find name, atomic number and average mass/weight
HAVE YOUR PERIODIC TABLE IN YOUR POSSESSION
Developed the 1st periodic table = Mendeleev