1. Chapter 4, Sec. 2 Atomic Structure & Atomic Structure Calculations
Physical Science
Chapter 4, Sec. 2
Atomic Structure &
Atomic Structure Calculations

2. Physical Science: Chapter 4: Atomic Structures & Calcs
Atoms of the same element have the same number of __________.
Hydrogen has ___
Helium has ___
Lithium has ___, etc.

3. Physical Science: Chapter 4: Atomic Structures & Calcs
Atomic Number (Z)
The _________________(Z) is the number of _____________in the ______________of an atom.
Atoms of the same _______have the same __________________.

4. Physical Science: Chapter 4: Atomic Structures & Calcs
Neutral atoms of elements ___________ _______________ of
protons and
electrons, so
these atoms alone
have ____________.

5. Physical Science: Chapter 4: Atomic Structures & Calcs
Mass Number (A)
The ____________(A) is the total number of ______________plus ____________in the nucleus. =
_______ _______ ________

6. Physical Science: Chapter 4: Atomic Structures & Calcs
Mini-Quiz #3 1). Name the three sub-atomic particles and their charges. 2). How do you calculate the mass number of an atom? 3). How do you determine the atomic number for an element?

7. Physical Science: Chapter 4: Atomic Structures & Calcs
Mini-Quiz #3 4). What is the atomic number (Z) and mass number (A) for the atom shown on the right?

8. Physical Science: Chapter 4: Atomic Structures & Calcs
Isotopes
Atoms of the SAME element (_____ _____________________) CAN have ______________________:
carbon-12 (mass = amu)
carbon-13 (mass = amu)
carbon-14 (mass = amu)

9. Physical Science: Chapter 4: Atomic Structures & Calcs
Isotopes
They must have ____________ numbers of ______________!
Atoms of the same element with different numbers of _________are called ________.

10. Physical Science: Chapter 4: Atomic Structures & Calcs
“Naming” Isotopes
Nuclear Symbol Notation:
mass number _______
the element symbol
atomic number ______
the element symbol.

11. What is the nuclear symbol for an isotope of nitrogen with 8 neutrons?
Physical Science: Chapter 4: Atomic Structures & Calcs
Nuclear symbol method:
What is the nuclear symbol for an isotope of nitrogen with 8 neutrons?

12. Physical Science: Chapter 4: Atomic Structures & Calcs
Hyphen Notation
Name of element – mass number.
_________ or ______
said as “carbon twelve”

13. Isotopes
You can “calculate” the structure of isotopes.
For each isotope you will know the atomic number (or be able to look it up on the Periodic Table) and you will know its mass number.
For U-235
Mass Number (A) = _______
Minus Atomic Number (Z) = - _______
Number of neutrons = _______

14. Physical Science: Chapter 4: Atomic Structures & Calcs
Mini-Quiz #4
1). How are isotopes of the same
element different?
2). Using hyphen notation write the
symbol for nitrogen with 7n0
(you may use a Periodic Table)
3). Using nuclear symbol notation, write
the symbol for chlorine with neutrons.

15. Physical Science: Chapter 4: Atomic Structures & Calcs
Mini-Quiz #4
4). How many neutrons are in an atom of
tritium 31H?
5). How many protons and neutrons are
in an atom of sulfur-33?

16. Physical Science: Chapter 4: Atomic Structures & Calcs
Atomic Mass Unit
● So the _____________________(_____) was created.
● 1amu = 1/12th mass of a carbon-12
atom, (no powers/exponents)
● For _______________, masses on the Periodic Table are in _________units.

17. Physical Science: Chapter 4: Atomic Structures & Calcs
Average Atomic Mass of an Element
Remember, many elements have _________.
Example:
carbon-12, carbon-13 & carbon-14
The mass for each isotope is slightly different, so the __________on the Periodic Table are ____________________of the masses of the ________________.

18. Avogadro’s Number
_________________(symbol ____) is the number of atoms in grams of carbon.
Its numerical value is _________________.
Therefore, a g sample of carbon contains _______________________carbon atoms.
The unit Mole comes from the word molecule, from the German word “Molekül” first used by Wilhelm Ostald of Germany in 1902.

19. __mol = __________number = __________units
Mole Calculations I
The ___________(mol) is a unit of measure for an amount of a chemical substance.
It is a basically just a ____________term for large numbers of things; think of a dozen, a score, a gross, etc.
A mole is Avogadro’s number of particles, which is ________________particles.
__mol = __________number = __________units
We can use the __________relationship to convert between the __________of ___________and the _________of a substance.

20. Moles and Molecules
Later

21. Mole Calculations I- Show all work!
How many carbon atoms are in mol C?
How many moles of aluminum are in 3.42 x 1021 atoms Al?
Calculate the number of sodium atoms in mol Na.
Calculate the number of molecules in mol of chlorine gas, Cl2.
Calculate the number of moles of potassium in 1.25 × 1021 atoms K.
Calculate the number of moles of iodine in × 1025 molecules of I2.

22. Mole Calculations II
Now we will use the _______________of an element/compound to convert between ____ of a substance and _______or __________of a substance.
__________particles = __ mol = _________(g)
If we want to convert particles to mass, we must first convert particles to moles, and then we can convert moles to mass.

23. Mole–Mass Calculation- Show all work!
What is the mass of 1.33 moles of titanium, Ti?
What is the mass (g) of 3.50moles of copper?
How many moles are in 11.9g of aluminum?
What is the mass of 2.55 x 1023 atoms of lead?
Mini-Quiz #5
How many grams of helium are there in 27.5 moles of helium?
How many moles of silicon are there in g of silicon?

24. Physical Science: Chapter 4: Atomic Structures & Calcs
CHAPTER REVIEW QUIZ
1). What is the DEFINITION of a mole?
2). What is Avogadro’s Number?
3). How many grams of helium are there
in moles of helium? (SHOW
your work)
4). How many moles of silicon are there
in g of silicon? (SHOW work)