Ions and Isotopes
Warm Up1. What’s the difference
between a unicycle, a bicycle and a tricycle? (aren’t they the same thing?)
2. How many protons, neutrons, and electrons does Oxygen have?
Objetivos• SWBAT distinguish
between atoms, isotopes, and ions.
• SWBAT calculate number of protons, neutrons, and electrons.
Agenda• Warm Up• Agenda• Revisit Atom• Fruit Loopy Atoms?• Ions & Isotopes• WS.4.2• Exit Ticket
Quiz tomorrow
Activity: Fruit Loopy Atoms Date
Background Info
Subatomic Particles
• Proton – heavy and +1 charge• Neutron – heavy and 0 charge• Electron – tiny and -1 charge
Electron ShellsElectron shell – orbit followed by electrons around
an atom’s nucleus.
How electron shells fill:
ELECTRON SHELL MAX NUMBER OF ELECTRONS
1ST 22ND 83rd 184th 32
Picture of a Beryllium Atom
Beryllium Atomic number:
Protons:Neutrons:Atomic mass: 9
• Atom = most common form of element, atoms are ALWAYS neutral (# protons = # electrons)
An atom has 5 protons … How many electrons does it have?
How can we tell atoms of different substances apart?
• Each type of atom has a different number of PROTONS
• ATOMIC NUMBER = # of PROTONS… what defines an element!
An atom has 82 protons … what element is it?
• Look for number 82 on your periodic table!!
How many electrons does it have?
• Atomic # = # Protons = # Electrons• 82 = 82 protons = 82 electrons
You Try!
Element Atomic Number Protons Electrons
8
So … in atoms protons = electrons
What about neutrons???
Atoms have DIFFERENT amounts of Neutrons!!
They are called ISOTOPES
Isotope = atoms with same # protons, different # of neutrons
How can we figure out how many neutrons an atom has?
The mass of an atom can be calculated by adding protons + neutrons!
Mass Number (sometimes all called “atomic number”) = # protons + # neutrons
Practice
Element Atomic Number (Protons!!!) Mass Number Neutrons
Neon 22 ?
Practice
Element Atomic Number Mass Number Neutrons
20 46
Atomic Weight
• Mass Number/Atomic Mass is not to be confused with atomic weight!
• Atomic weight = weighted average of the atomic masses of the different isotopes of an element
• Where is atomic weight on your PToE?
16
S32.065
Ion
• Ion = an atom that has either lost or gained electrons and now has a + or - charge
• Materials/Methods: You will build an atom from the periodic table using a paper plate, fruit loops, and glue. It is important that you both use the same color for the same sub atomic particles.
Pick your Partner
• Choose someone who know you will work well with
• Move to a desk beside them
Fruit Loop Atoms
• Complete first part of the Fruit Loop Activity• When you reach a , you should probably stop.
•Make an ATOM of Lithium, Beryllium, or Boron
Isotope
An isotope is an atom with the same # of protons and electrons but a different # of neutrons.
Example: The most common type of sulfur usually has 16 neutrons, but sometimes an isotope of sulfur will have 17 neutrons.
** Number of protons and electrons the same!
Notes
Isotope
Scientists like to have a quick way to write down isotopes! There are two ways:
C – 14 Mass Number
Notes
H21
Mass Number
Example
• Write the isotope symbol in two ways for an isotope of fluorine that has a mass number of 22.
You Try!You Try! Notes
IsotopeElement Symbol Atomic Mass Protons Neutrons Electrons
Sr - 92
Cr – 60 24
Gold 203 79
Fill out the chart with your partner, then make a fruit loop isotope for
Li – 9, Be – 11, B - 14.
Notes
Ion
An ion is an atom with the same number of protons and neutrons but a different number of electrons.
This means the charge is no longer neutral!
Two types: Cation = positive ion, lost electronsAnion = negative ion, gained electrons
Notes
Ion
Meet the atom’s family!
Symbols:
C4- F1+
Notes
New Electric Charge
IonElement Symbol Atomic Mass Protons Neutrons Electrons
Sr 2+
Cr3+ 24
Fluorine 19 10
Fill out the chart with your partner, then make a fruit loop Ion.
Li1+, Be2+, B2-. **Use the same # of neutrons as
when you made the original atom.
Notes
Conclusion
• 1. How are each of your three atoms different?• 2. Why are the masses of the atom of the element and
the isotope different?• 2. Calculate the average weight of your element. (Take
the average of the atomic mass of the original atom and the atomic mass of the isotope.) Average weight= __________________________________
• 3. Are the atomic weights on the periodic table whole numbers or decimals?
• 4. Why do you think the atomic weights are this way?
Complete WS 4.2
Warm Up1. You have 3 skittles. The
mass of all the skittles is 9 g. What is the mass of each skittle?
2. A bag of M&M’s has 40 M&M’s. There are 10 blue M&M’s. What percentage of all the M&M’s are blue?
???• EQ: How do we calculate
average atomic weight?• HOT Q1: What does
percent abundance mean?
• HOT Q2: Why are the atomic weights on the PToE decimal numbers?
• HOT Q3: What terms do we need to define for our quiz?
Agenda
• Warm Up • Agenda• Beanium• Quiz!• Exit Ticket
Beanium
• On a periodic table, the values for atomic number and atomic weight are given for each element. The atomic number is the whole number and represents the number of protons in the atom. The atomic weight is a decimal number because it represents a weighted average of the masses of the isotopes of each element.
• In the following lab, you will determine the average atomic weight for the element “beanium”. There are three naturally occurring isotopes of beanium: white-beanium (must have a black dot!), brown-beanium, and speckled-beanium. You will calculate the average atomic weight of a given sample of beanium.
When You Get to Your Lab Station…
• READ the directions
• If you are confused– 1) THINK– 2) Ask a person at your lab station BEFORE you ask
Ms. Hoffman – 3) Ms. Hoffman is your last resort
At the lab station…
• You are 30 minutes to complete this activity
• By the end of 30 minutes, you have answered ALL questions on lab handout
Classroom Leaders!• People I will be pulling out to meet with:
– Tucker– Ken’Dajha– Nigel– Kiana– Justin– Jalisa– Jenn– Aysha– Krishanni– Nevada– Josh
Beanium• 1. Separate the “atoms” of beanium in your
sample into three groups based on type of isotope (white, brown, or speckled). THROW OUT ALL WHITE BEANS THAT DO NOT HAVE A BLACK DOT. Count the number of atoms of each isotope and record below:
Isotope # of Atoms
White Beanium Atoms
Brown Beanium Atoms
Speckled Beanium Atoms
• 2. Using your balance, find the mass of each isotope in the sample and record below:
Isotope Total MassWhite Beanium AtomsBrown Beanium Atoms
Speckled Beanium Atoms
• 3. Calculate the grams in one atom of each isotope and record below. To find the mass of one atom of beanium – divide the total mass by the number of atoms you have for that element. Example: Total Mass of White Beanium / # of White Beanium Atoms
Isotope Atomic MassWhite Beanium AtomsBrown Beanium Atoms
Speckled Beanium Atoms
4. Determine the percent abundance of each isotope in your sample. This can be done by
dividing the number of atoms of each isotope by the total number of atoms in your
sample and multiplying by 100. Example: ( # of white beanium atoms / Total #
of atoms ) * 100Isotope % Abundance
White Beanium AtomsBrown Beanium Atoms
Speckled Beanium Atoms
Vocab Quiz!• Define the following terms:–Proton–Neutron–Electron–Atom–Atomic Number– Isotope–Mass Number (also called “atomic mass”)– Ion
Quiz!• Define the following terms:– Proton– Neutron– Electron– Atom– Atomic Number– Isotope– Mass Number (also called “atomic mass”)– Ion– Cation– Anion
Practice
Substance: HeliumSymbol: HeAtomic Number: 2Mass Number: 4Number of Protons: Number of Neutrons: Number of Electrons:
Substance: MagnesiumSymbol: Atomic Number: 12Mass Number: 24Number of Protons: 12Number of Neutrons: Number of Electrons:
Substance:Symbol: ZnAtomic Number: 30Mass Number: 65Number of Protons: Number of Neutrons: Number of Electrons:
Substance: BromineSymbol: BrAtomic Number: Mass Number: 80Number of Protons: Number of Neutrons: Number of Electrons: 35
Substance: Symbol: Atomic Number: 13Mass Number: Number of Protons: 14Number of Neutrons: 14Number of Electrons:
Substance: UraniumSymbol: UAtomic Number: Mass Number: Number of Protons: Number of Neutrons: 146Number of Electrons: 92
Substance: SodiumSymbol: Atomic Number: 11Mass Number: Number of Protons: Number of Neutrons: 12Number of Electrons:
Substance: KryptonSymbol: KrAtomic Number: Mass Number: Number of Protons: Number of Neutrons: 48Number of Electrons: 36
Substance: Symbol: CaAtomic Number: Mass Number: 40Number of Protons: 20Number of Neutrons: Number of Electrons:
Substance: Oxide ionSymbol: O2-
Atomic Number: 8Mass Number: 16Number of Protons: Number of Neutrons: Number of Electrons:
Substance: ChlorideSymbol: Cl-1
Atomic Number: Mass Number: 35Number of Protons: Number of Neutrons: 17Number of Electrons:
Substance: Strontium ionSymbol: Sr 2+
Atomic Number: Mass Number: 36Number of Protons: 18Number of Neutrons: Number of Electrons:
Exit Ticket
Use your periodic table of awesomeness!
1. What is the “average atomic weight”?
2. What is the mass number of C – 15?
3. How many neutrons does C-15 have?