Q: How are compounds and mixtures different? A. Compounds and mixtures are not different. B. Mixtures and compounds can both be separated physically. C. Compounds can be separated physically, but mixtures must be separated by a chemical reaction. D. Mixtures can be separated physically, but compounds must be separated by a chemical reaction. SC8.2.1.a DOK 2

A: How are compounds and mixtures different? A. Compounds and mixtures are not different. Compounds must be separated by a chemical reaction, but mixtures can be separated physically. B. Mixtures and compounds can both be separated physically. Mixtures can be separated physically, but compounds cannot. C. Compounds can be separated physically, but mixtures must be separated by a chemical reaction. D. Mixtures can be separated physically, but compounds must be separated by a chemical reaction. For example, a mixture like salt water can be separated physically into salt and water by boiling the water out. In order for a compound like water (H2O) to be separated into hydrogen and oxygen, a chemical reaction must occur. SC8.2.1.a DOK 2

Explain How do we find the number of protons, electrons, and neutrons there are in the element Copper.

A. The student did not state a hypothesis. A student flips a coin ten times. It lands on heads 7 times and tails 3 times. The student concludes that a coin lands on heads more than tails. Why could the student’s conclusion be wrong, even though it agrees with the results? A. The student did not state a hypothesis. B. The student should have flipped the coin only twice. C. The student’s results would probably differ if more data was collected. D. The student’s conclusion is not wrong, it does not matter how many times the coin is flipped. SC8.1.1.f DOK 2

A: A student flips a coin ten times A: A student flips a coin ten times. It lands on heads 7 times and tails 3 times. The student concludes that a coin lands on heads more than tails. Why could the student’s conclusion be wrong, even though it agrees with the results? A. The student did not state a hypothesis. The hypothesis is not related to the number of trials performed. B. The student should have flipped the coin only twice. The more data that is collected the more valid the results would be. C. The student’s results would probably differ if more data was collected. There are only two sides to the coin so there is a 50% chance of heads and a 50% chance of tails each time. The more times the coin is flipped the more likely the results will turn out 50% heads and 50% tails. D. The student’s conclusion is not wrong, it does not matter how many times the coin is flipped. SC8.1.1.f DOK 2

Agenda Notes on Isotopes Isotope Demo Calculating Average Atomic Mass Gaining an electron leads to O-, Gaining a proton makes it Fluorine, and gaining a neutron changes the atomic mass, creating a new isotope.

Today’s Objectives I will know how isotopes form. I will be able to calculate the atomic mass of an element based on percentages of isotopes.

Isotopes Isotopes are atoms of the same element type that have different numbers of neutrons Neutrons have NO CHARGE, so they only change the mass of the atom . Remind students that when the number of electrons changes, an ion is formed. Today we’ll be talking about what happens when the number of neutrons changes. The number of protons in an element will always be the same. These are all atoms of hydrogen

One way to show Isotopes: Carbon-12 Carbon-14 Atomic Mass Protons Electrons Neutrons The mass number gives the number of protons and neutrons.

Let’s Practice Oxygen has 3 isotopes: oxygen-16 oxygen-17 oxygen-18 How many of each subatomic particle are in each of the isotopes of oxygen? Oxygen-16 Oxygen-17 Oxygen-18 Atomic Mass Protons Electrons Neutrons Oxygen has 8 protons and 8 electrons. Oxygen-16 has 8 neutrons, oxygen-17 has 9 neutrons, and oxygen-18 has 10 neutrons.

A second way to show Isotopes These symbols show two isotopes of carbon. Point out that the mass changes because of the different numbers of neutrons.

Write the symbols for the following isotopes using isotope notation. Let’s Practice Write the symbols for the following isotopes using isotope notation. A.) Magnesium – 24 B.) Carbon – 13 C.) Silver – 108 The answer will come up after clicking to advance the animation.

Let’s Practice Calculate the number of protons, neutrons, and electrons in an atom of zirconium-90 that has no overall charge and an atomic number of 40.

Answer Number of protons = atomic number 40 Number of neutrons = mass number – atomic number = 50 Number of electrons = number of protons = 40

What do you think? Why is the atomic mass on the periodic table not a whole number? If students struggle coming up with the answer (it’s an average), give examples of other times when averages might be used. (batting average, GPA, etc)

Calculating the Mass of an Element The atomic mass of an element is the weighted average of the masses of all the naturally occurring isotopes of that element. Have students write down this definition.

Calculating Atomic Mass Chlorine-35 makes up 76% of all the chlorine in nature, and chlorine-37 makes up the other 24%. What is the atomic mass of chlorine? Step 1: Multiply the mass number of each isotope by its percentage abundance in decimal form. (35 x 0.76) = 26.60 (37 x 0.24) = 8.88 Step 2: Add these amounts together to find the atomic mass. 26.60 + 8.88 = 35.48 amu Demonstrate finding the average atomic mass.

Let’s Practice The metal thallium occurs naturally as 30% thallium-203 and 70% thallium-205. Calculate the atomic mass of thallium. As a class, find the average atomic mass of thallium.

Answer (0.30 x 203 amu) + (0.70 x 205 amu) = 204.4 amu

Let’s Practice Calculate the atomic mass of gallium, which consists of 60% gallium-69 and 40% gallium-71.

Answer (0.60 x 69 amu) + (0.40 x 71 amu) = 69.8 amu

Assignment (Take Home Quiz) Pg 121 Reviewing Content #4-10 Understanding Concepts #16-19 & 21 Critical Thinking #24, 28, & 29 Math Skills #30-32