1. Honors Unit 02 Lesson 02: The Structure of Atoms
Atoms and Elements
Chemistry Honors Unit 02
Based on the PowerPoints by Kevin Boudreux.
Honors Unit 02 Lesson 02: The Structure of Atoms

2. Honors Unit 02 Lesson 02: The Structure of Atoms
Lesson 2 Index
The Atomic Theory Today
The Atom and the Subatomic Particles
Atomic Number, Mass Number, and Isotopes
Atomic Symbols
Ions
Hyphen notation of isotopes
Nuclear notation of isotopes
Isotope Examples
Tutorials EPN
Tutorials - Isotopes
Honors Unit 02 Lesson 02: The Structure of Atoms

3. Honors Unit 02 Lesson 02: The Structure of Atoms

4. The Atomic Theory Today
An atom is an electrically neutral, spherical entity composed of a positively charged central nucleus surrounded by one or more negatively charged electrons.
The nucleus contains about 99.7% of the atom’s mass, but occupies 1 ten-trillionth of its volume.
The nucleus contains the protons, which have positive charges, and neutrons, which are neutral. Neutrons are very slightly heavier than protons; protons are 1835 times heavier than electrons.
The electrons (e-) surrounding the nucleus have negative charges. The number of protons in the nucleus equals the number of electrons surrounding the nucleus in a neutral atom.
Honors Unit 02 Lesson 02: The Structure of Atoms

5. Honors Unit 02 Lesson 02: The Structure of Atoms
Modern Atomic Theory
All matter is composed of atoms.
Atoms of one element differ in properties from atoms of another element.
Atoms are divisible into smaller particles called subatomic particles
A given element is made up of atoms with different masses. (Isotopes)
Chemical reaction involves only the combination, separation, or rearrangement of atoms.
Compounds are formed by the combination of atoms in small whole number ratios.
Honors Unit 02 Lesson 02: The Structure of Atoms

6. The Atom and the Subatomic Particles
Honors Unit 02 Lesson 02: The Structure of Atoms

7. The Atom and the Subatomic Particles
Honors Unit 02 Lesson 02: The Structure of Atoms

8. Atomic Number, Mass Number, and Isotopes
What makes elements different from one another is the number of protons in their atoms, called the atomic number (Z). All atoms of the same element contain the same number of protons.
The mass number (A) is the sum of the number of protons (Z) and neutrons (N) in the nucleus of an atom: A = Z + N
Isotopes of an element have the same atomic number, but different #’s of neutrons. Isotopes of an element have nearly identical chemical behavior.
Honors Unit 02 Lesson 02: The Structure of Atoms

9. Atomic Number (z) Summarized
Symbol = z
Number of protons (+).
On periodic table.
# of protons determines the element
(Add a proton to oxygen it becomes fluorine – nuclear reactions only)
For a neutral atom, # electrons = # protons
Honors Unit 02 Lesson 02: The Structure of Atoms

10. Mass Number (A) Abridged Version
Total number of protons and neutrons.
Not on the periodic table.
Determines the isotope.
A = #neutrons + #protons
#neutrons = A - #protons
bigger number
Close to the mass of the isotope.
Honors Unit 02 Lesson 02: The Structure of Atoms

11. Honors Unit 02 Lesson 02: The Structure of Atoms

12. Honors Unit 02 Lesson 02: The Structure of Atoms

13. Honors Unit 02 Lesson 02: The Structure of Atoms
Atomic Symbols
The atomic symbol specifies information about the nuclear mass (i.e. the mass number), atomic number, and the charge on a particular element. Every element has a one- or two-letter symbol based on its English or Latin name.
Honors Unit 02 Lesson 02: The Structure of Atoms

14. Honors Unit 02 Lesson 02: The Structure of Atoms
Sometimes referred to as nuclear notation or isotopic notation.
Honors Unit 02 Lesson 02: The Structure of Atoms

15. Honors Unit 02 Lesson 02: The Structure of Atoms
Ions
Neutral atoms have the same numbers of electrons as protons. In many chemical reactions, atoms gain or lose electrons to form charged particles called ions.
For example, sodium loses one electron, resulting in a particle with 11 protons and 10 electrons, having a +1 charge:
Positively charged ions are called cations.
Fluorine gains one electron, resulting in a particle with 9 protons and 10 electrons, having a -1 charge:
Negatively charged ions are called anions.
Honors Unit 02 Lesson 02: The Structure of Atoms

16. Hyphen notation of isotopes
“isotope” hyphen “mass number”
Isotope-A
Carbon-12
Oxygen-18
Honors Unit 02 Lesson 02: The Structure of Atoms

17. Nuclear or Isotopic Notation of Isotopes
A= mass #
Z=atomic #
X=element
Big number on top.
Carbon-14
Honors Unit 02 Lesson 02: The Structure of Atoms

18. Important Facts about Subatomic Particles
# of electrons determines the charge of the atom
#e- = #p+ Charge is zero (neutral)
#e- > #p+ (greater than) Charge is negative.
#e- < #p+ (less than) Charge is positive.
# of protons determines what element it is.
# of protons and neutrons determines the mass of the atom. (Since electron’s mass ~0)
An electron and proton can combine to form a neutron and vice versa. (nuclear reactions only)
A neutron has the most mass.
Honors Unit 02 Lesson 02: The Structure of Atoms

19. How to Determine the Number of e-, p+ & n
#p+ = atomic #
If charge = 0, then #p+ = #e-
#e- = #p+ - charge
#e- - reason it out – Who’s wining? By how much?
charge = #p+ - #e-
#n = A – Z (mass # - atomic #)
Honors Unit 02 Lesson 02: The Structure of Atoms

20. Honors Unit 02 Lesson 02: The Structure of Atoms
Example
How many protons? Electrons? Ca
Honors Unit 02 Lesson 02: The Structure of Atoms

21. Honors Unit 02 Lesson 02: The Structure of Atoms
Example
How many protons? electrons?
Mg2+
Honors Unit 02 Lesson 02: The Structure of Atoms

22. Honors Unit 02 Lesson 02: The Structure of Atoms
Examples
How many electrons? F-
Honors Unit 02 Lesson 02: The Structure of Atoms

23. Honors Unit 02 Lesson 02: The Structure of Atoms
Example
How many protons? electrons?
P3-
Honors Unit 02 Lesson 02: The Structure of Atoms

24. Honors Unit 02 Lesson 02: The Structure of Atoms
Your Turn
How many protons? Electrons? Mg
Honors Unit 02 Lesson 02: The Structure of Atoms

25. Honors Unit 02 Lesson 02: The Structure of Atoms
Your Turn
How many protons? Electrons? Li
Honors Unit 02 Lesson 02: The Structure of Atoms

26. Honors Unit 02 Lesson 02: The Structure of Atoms
Your Turn
How many protons? Electrons? Cu
Honors Unit 02 Lesson 02: The Structure of Atoms

27. Honors Unit 02 Lesson 02: The Structure of Atoms
Your Turn
How many protons? electrons? K+
Honors Unit 02 Lesson 02: The Structure of Atoms

28. Honors Unit 02 Lesson 02: The Structure of Atoms
Your Turn
How many protons? electrons?
S2-
Honors Unit 02 Lesson 02: The Structure of Atoms

29. Honors Unit 02 Lesson 02: The Structure of Atoms
Example
How many protons, electrons, and neutrons does carbon-14 have? (A=14)
Honors Unit 02 Lesson 02: The Structure of Atoms

30. Honors Unit 02 Lesson 02: The Structure of Atoms
#Neutrons
How many protons, electrons, and neutrons does neon-22 have? (A=22)
Honors Unit 02 Lesson 02: The Structure of Atoms

31. Honors Unit 02 Lesson 02: The Structure of Atoms
Your turn
How many neutrons does oxygen-18 have? (A=18)
Honors Unit 02 Lesson 02: The Structure of Atoms

32. Honors Unit 02 Lesson 02: The Structure of Atoms
Your turn
How many protons, electrons, and neutrons does Silicon-30 have? (A=30)
Honors Unit 02 Lesson 02: The Structure of Atoms

33. Honors Unit 02 Lesson 02: The Structure of Atoms
Your turn
Determine the number of protons, electrons, and neutrons of Boron-12.
Honors Unit 02 Lesson 02: The Structure of Atoms

34. Hyphen notation examples
Put in hyphen notation
A nuclide of fluorine has 9 protons and 10 neutrons.
Honors Unit 02 Lesson 02: The Structure of Atoms

35. Hyphen notation of isotopes
“isotope” hyphen “mass number”
Isotope-A
Carbon-12
Oxygen-18
Honors Unit 02 Lesson 02: The Structure of Atoms

36. Hyphen notation examples
Put in hyphen notation
A nuclide of calcium has a mass number of 44 and an atomic number of 20.
Honors Unit 02 Lesson 02: The Structure of Atoms

37. Hyphen notation examples
Put in hyphen notation
A nuclide of nickel has a 28 protons and 32 neutrons.
Honors Unit 02 Lesson 02: The Structure of Atoms

38. Honors Unit 02 Lesson 02: The Structure of Atoms
Your turn
Put in hyphen notation
A nuclide of arsenic has an atomic number of 33 and a mass number of 75
Honors Unit 02 Lesson 02: The Structure of Atoms

39. Honors Unit 02 Lesson 02: The Structure of Atoms
Your turn
Put in hyphen notation
An unknown nuclide has a 30 protons and 34 neutrons.
Honors Unit 02 Lesson 02: The Structure of Atoms

40. Honors Unit 02 Lesson 02: The Structure of Atoms
Your turn
Put in hyphen notation
A nuclide has a 37 protons and 48 neutrons.
Honors Unit 02 Lesson 02: The Structure of Atoms

41. Nuclear or Isotopic Notation of Isotopes
A= mass #
Z=atomic #
X=element
Big number on top.
Carbon-14
Honors Unit 02 Lesson 02: The Structure of Atoms

42. Nuclear notation Examples
Put in nuclear notation.
A nuclide has 8 protons and 8 neutrons.
Honors Unit 02 Lesson 02: The Structure of Atoms

43. Nuclear notation Examples
Put in nuclear notation.
A nuclide has a mass number of 130 and an atomic number of 56.
Honors Unit 02 Lesson 02: The Structure of Atoms

44. Nuclear notation Examples
Determine the number of electrons, neutrons, and protons of:
Honors Unit 02 Lesson 02: The Structure of Atoms

45. Honors Unit 02 Lesson 02: The Structure of Atoms
Your turn
Determine the number of electrons, neutrons, and protons of:
Honors Unit 02 Lesson 02: The Structure of Atoms

46. Honors Unit 02 Lesson 02: The Structure of Atoms
Your turn
Determine the number of electrons, neutrons, and protons of:
Honors Unit 02 Lesson 02: The Structure of Atoms

47. Honors Unit 02 Lesson 02: The Structure of Atoms
Your turn
Put in nuclear notation. Tin-113
Honors Unit 02 Lesson 02: The Structure of Atoms

48. Honors Unit 02 Lesson 02: The Structure of Atoms
Your turn
Put in nuclear notation. A nuclide has 27 protons, 30 neutrons, and 24 electrons.
Honors Unit 02 Lesson 02: The Structure of Atoms

49. Honors Unit 02 Lesson 02: The Structure of Atoms

50. Honors Unit 02 Lesson 02: The Structure of Atoms
Tutorials EPN
Tutorials on how to find the number of electrons, protons, and neutrons
Honors Unit 02 Lesson 02: The Structure of Atoms

51. Honors Unit 02 Lesson 02: The Structure of Atoms
Tutorials - Isotopes
Tutorials for writing the isotopes in hyphen notation or nuclear (isotopic) notation
Honors Unit 02 Lesson 02: The Structure of Atoms