Download - The Atom Atomic Number Mass Number Isotopes Elements Periodic Table Chapter 4 Atoms and Elements
• The Atom• Atomic Number • Mass Number• Isotopes• Elements• Periodic Table
Chapter 4
Atoms and Elements
What do all of these things have in common?
What Are Atoms?
• Atoms are the building blocks of matter.
• So what is “matter”?• Anything that has mass AND takes up
space.• Examples:
Atomic Theory
Atoms are the building blocks
of all matter, which included
elements
Democritus, JJ Thomson, E
Rutherford, N Bohr, Chadwick,
Shrodinger, current wave
theory
What Are Elements?
Pure substances made up of all the same type of atom (same # of: p+, n, e-)
The 4 most abundant elements on Earth are carbon, oxygen, hydrogen, and nitrogen (POINTER: COHN or NOCH)
112 elements known todayExamples: carbon
goldcalcium
What element do these things have in common?
Here’s a Hint…
IRON (Fe) Latin: ferrum
• Cheapest…• Most common…• Most useful…
• Used extensively for the making of STEEL
IRON (Fe) Latin: ferrum
It also carries oxygen in hemoglobin in red blood cells.
% Major Elements in the Body
O 65.0 % K 0.34C 18.0 S 0.26H 10.0 Na 0.14N 3.0 Cl 0.14Ca 1.4 Fe 0.004P 1.0 Zn 0.003 Mg 0.50
Symbols of Elements
Use 1 or 2 letter abbreviations Capitalize the first letter only
Examples:C carbon Co cobaltN nitrogen Ca calciumF fluorine Br bromine
O oxygen Mg magnesium
Symbols from Latin NamesElement Symbol Latin nameCopper Cu cuprumGold Au aurumLead Pb plumbumMercury Hg hydrargyrumPotassium K kaliumSilver Ag argentumSodium Na natriumTin Sn stannum
Take a guess what the correct symbol is for the element!
Select the correct symbol for each:A. Calcium
1) C 2) Ca 3) CAB. Sulfur
1) S 2) Sl 3) SuC. Iron
1) Ir 2) FE 3) Fe
Take a guess what the correct element is! Select the correct name for each:A. N
1) neon 2) nitrogen 3) nickelB. P
1) potassium2) phogiston3) phosphorus
C. Ag1) silver 2) agean3) gold
Periodic Table
The periodic table is an arrangement of the elements according to:
•The number of protons, neutrons, and electrons
•The way they look•The way they act
The Periodic Table
Shows the mass number and atomic
number
Gives the symbol of the element
mass number
23 Na or Na-23
atomic number 11
Groups of Elements
Vertical (up and down) columns
on the periodic table
Indicates the number of
electrons on the outer most shell
called valence electrons.
Periods on the Periodic Table
Horizontal (left to right) rows on the
Periodic Table.
Numbered 1-7
Indicates the number of
orbitals or shells the element
has.
Periods on the Periodic Table
123456
Using The Periodic Table
• In your notes, use your periodic tables to determine the following for the elements at the bottom.• The number of protons• The number of neutrons• The number of electrons on the outer most
shell (valence electrons)
•Calcium (Ca), Magnesium (Mg), Chlorine (Cl)
Subatomic Particles: Smaller Parts of an Atom
Particle Symbol Charge
Electron e- -1
Proton p+ +1
Neutron n 0
Location of Subatomic Particles
10-13 cm
electrons
protons
neutrons
10-8 cm
nucleus
Vocabulary
Neutral atoms = # of protons = # of electronsMass Number = # of p+ + # of nAtomic Number = # of protons Atomic Mass- the average mass of all of the isotopes.ion (unequal #’s of protons and electrons).
Cation-positive ionAnion – negative ion
Atomic Number
Counts the number of
?in an atom
protons
Ions• Cations
• Lost electrons (to other atoms)• When calculating number of e- subtract the
charge value from the original number of electrons.
• Anions• Gained electrons (from other atoms)• When calculating number of e- add the
charge value from the original number of electrons
Mass #
Counts the number of
? + ?in an atom
Protons and neutrons
Atomic Mass
Masses of theof
? isotopes
Subatomic Particles in Some Atoms
16 31 65 O P Zn
8 15 30
8 p+ 15 p+ 30 p+
8 n 16 n 35 n8 e- 15 e- 30 e-
Which number do you think is the atomic number? How do you know?
Drawing Bohr Diagrams
• Nucleus (p+ and no)• 1st energy level= up to 2 e-• 2nd energy level = up to 8e-• 3rd energy level = up to 18 e-• 4th energy level = 2 fill before 11-
18 in the 3rd energy level.
Bohr Diagrams
Electron Dot Diagram
• The symbol is the nucleus and inner energy levels
• Dots represent valence electrons• 8 total (2 on each side of symbol)• One each side, counterclockwise.
Electron dot diagrams
What Are Isotopes?
Atoms with the same number of protons,
but different numbers of neutrons.
Atoms of the same element (same atomic number) with different atomic masses.
Isotopes of Chlorine
35Cl 37Cl17 17
chlorine - 35 chlorine - 37
Learning Check
Naturally occurring carbon consists of three isotopes, C-12, C-13, and C-14. State the number of protons, neutrons, and electrons in each of these carbon atoms.
12C 13C 14C 6 6 6
#p _______ _______ _______
#n _______ _______ _______
#e _______ _______ _______
6
6
6
6
7
6
6
8
6
Calculating Average Atomic Mass
• Mass = (% x mass) + (% x mass)• 2 isotopes
• Mass = (% x mass) + (% x mass) + (% x mass)• 3 isotopes
• Make sure that % are in decimal form in your Calculator!!!!!