1. Honors Unit 02 Module 03: The Structure of Atoms
Atoms and Elements
Chemistry Unit 02
Based on the PowerPoints by Kevin Boudreux.
Honors Unit 02 Module 03: The Structure of Atoms

2. Honors Unit 02 Module 03: The Structure of Atoms

3. The Atom and the Subatomic Particles
Honors Unit 02 Module 03: The Structure of Atoms

4. The Atom and the Subatomic Particles
Honors Unit 02 Module 03: The Structure of Atoms

5. 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 Module 03: The Structure of Atoms

6. 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 Module 03: The Structure of Atoms

7. 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 Module 03: The Structure of Atoms

8. Honors Unit 02 Module 03: The Structure of Atoms

9. Honors Unit 02 Module 03: The Structure of Atoms

10. Honors Unit 02 Module 03: 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 Module 03: The Structure of Atoms

11. Honors Unit 02 Module 03: The Structure of Atoms
Sometimes referred to as nuclear notation or isotopic notation.
Honors Unit 02 Module 03: The Structure of Atoms

12. Honors Unit 02 Module 03: 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 Module 03: The Structure of Atoms

13. Hyphen notation of isotopes
“isotope” hyphen “mass number”
Isotope-A
Carbon-12
Oxygen-18
Honors Unit 02 Module 03: The Structure of Atoms

14. Nuclear or Isotopic Notation of Isotopes
A= mass #
Z=atomic #
X=element
Big number on top.
Carbon-14
Honors Unit 02 Module 03: The Structure of Atoms

15. 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 Module 03: The Structure of Atoms

16. 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 Module 03: The Structure of Atoms

17. Honors Unit 02 Module 03: The Structure of Atoms
Example
How many protons? Electrons? Ca
Honors Unit 02 Module 03: The Structure of Atoms

18. Honors Unit 02 Module 03: The Structure of Atoms
Example
How many protons? electrons?
Mg2+
Honors Unit 02 Module 03: The Structure of Atoms

19. Honors Unit 02 Module 03: The Structure of Atoms
Examples
How many electrons? F-
Honors Unit 02 Module 03: The Structure of Atoms

20. Honors Unit 02 Module 03: The Structure of Atoms
Example
How many protons? electrons?
P3-
Honors Unit 02 Module 03: The Structure of Atoms

21. Honors Unit 02 Module 03: The Structure of Atoms
Your Turn
How many protons? Electrons? Mg
Honors Unit 02 Module 03: The Structure of Atoms

22. Honors Unit 02 Module 03: The Structure of Atoms
Your Turn
How many protons? Electrons? Li
Honors Unit 02 Module 03: The Structure of Atoms

23. Honors Unit 02 Module 03: The Structure of Atoms
Your Turn
How many protons? Electrons? Cu
Honors Unit 02 Module 03: The Structure of Atoms

24. Honors Unit 02 Module 03: The Structure of Atoms
Your Turn
How many protons? electrons? K+
Honors Unit 02 Module 03: The Structure of Atoms

25. Honors Unit 02 Module 03: The Structure of Atoms
Your Turn
How many protons? electrons?
S2-
Honors Unit 02 Module 03: The Structure of Atoms

26. Honors Unit 02 Module 03: The Structure of Atoms
Example
How many protons, electrons, and neutrons does carbon-14 have? (A=14)
Honors Unit 02 Module 03: The Structure of Atoms

27. Honors Unit 02 Module 03: The Structure of Atoms
#Neutrons
How many protons, electrons, and neutrons does neon-22 have? (A=22)
Honors Unit 02 Module 03: The Structure of Atoms

28. Honors Unit 02 Module 03: The Structure of Atoms
Your turn
How many neutrons does oxygen-18 have? (A=18)
Honors Unit 02 Module 03: The Structure of Atoms

29. Honors Unit 02 Module 03: The Structure of Atoms
Your turn
How many protons, electrons, and neutrons does Silicon-30 have? (A=30)
Honors Unit 02 Module 03: The Structure of Atoms

30. Honors Unit 02 Module 03: The Structure of Atoms
Your turn
Determine the number of protons, electrons, and neutrons of Boron-12.
Honors Unit 02 Module 03: The Structure of Atoms

31. Hyphen notation examples
Put in hyphen notation
A nuclide of fluorine has 9 protons and 10 neutrons.
Honors Unit 02 Module 03: The Structure of Atoms

32. Hyphen notation of isotopes
“isotope” hyphen “mass number”
Isotope-A
Carbon-12
Oxygen-18
Honors Unit 02 Module 03: The Structure of Atoms

33. 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 Module 03: The Structure of Atoms

34. Hyphen notation examples
Put in hyphen notation
A nuclide of nickel has a 28 protons and 32 neutrons.
Honors Unit 02 Module 03: The Structure of Atoms

35. Honors Unit 02 Module 03: 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 Module 03: The Structure of Atoms

36. Honors Unit 02 Module 03: The Structure of Atoms
Your turn
Put in hyphen notation
An unknown nuclide has a 30 protons and 34 neutrons.
Honors Unit 02 Module 03: The Structure of Atoms

37. Honors Unit 02 Module 03: The Structure of Atoms
Your turn
Put in hyphen notation
A nuclide has a 37 protons and 48 neutrons.
Honors Unit 02 Module 03: The Structure of Atoms

38. Nuclear or Isotopic Notation of Isotopes
A= mass #
Z=atomic #
X=element
Big number on top.
Carbon-14
Honors Unit 02 Module 03: The Structure of Atoms

39. Nuclear notation Examples
Put in nuclear notation.
A nuclide has 8 protons and 8 neutrons.
Honors Unit 02 Module 03: The Structure of Atoms

40. Nuclear notation Examples
Put in nuclear notation.
A nuclide has a mass number of 130 and an atomic number of 56.
Honors Unit 02 Module 03: The Structure of Atoms

41. Nuclear notation Examples
Determine the number of electrons, neutrons, and protons of:
Honors Unit 02 Module 03: The Structure of Atoms

42. Honors Unit 02 Module 03: The Structure of Atoms
Your turn
Determine the number of electrons, neutrons, and protons of:
Honors Unit 02 Module 03: The Structure of Atoms

43. Honors Unit 02 Module 03: The Structure of Atoms
Your turn
Determine the number of electrons, neutrons, and protons of:
Honors Unit 02 Module 03: The Structure of Atoms

44. Honors Unit 02 Module 03: The Structure of Atoms
Your turn
Put in nuclear notation. Tin-113
Honors Unit 02 Module 03: The Structure of Atoms

45. Honors Unit 02 Module 03: The Structure of Atoms
Your turn
Put in nuclear notation. A nuclide has 27 protons, 30 neutrons, and 24 electrons.
Honors Unit 02 Module 03: The Structure of Atoms

46. Honors Unit 02 Module 03: The Structure of Atoms

47. Honors Unit 02 Module 03: The Structure of Atoms
Tutorials EPN
Tutorials on how to find the number of electrons, protons, and neutrons
Honors Unit 02 Module 03: The Structure of Atoms

48. Honors Unit 02 Module 03: The Structure of Atoms
Tutorials - Isotopes
Tutorials for writing the isotopes in hyphen notation or nuclear (isotopic) notation
Honors Unit 02 Module 03: The Structure of Atoms