Catalyst 1.What’s the difference between fission and fusion reactions? 2.How much energy would be produced if this mass was converted to energy if you have 2 kg of a substance?

DateDescriptionPage 5/21/ Isotopes Radioactive decay

LECTURE 10.3– ISOTOPES

Today’s Learning Targets I can explain what an isotope of an element is. I can discuss the three forms of decay that radioactive isotopes can undergo and how the nucleus is altered in each type of decay. I can list the three different types of radiation and the impact that each one of these types of decay can have on myself and other living matter

What are isotopes?

Make some observations: What stays the same? What is different for each m&m? (L)

Make some observations: What stays the same? What is different for each element? (L)

Based on the last two slides, what is the definition of an isotope? (R) Be clear about what stays the same and what changes Use your knowledge of what defines an atom/subatomic particles

Based on the last two slides, what is the definition of an isotope? (R) An isotope of an element has the Same number of protons Different number of neutrons Different atomic mass

What about the number of electrons? Do you think they are the same or different for isotopes? Why?

What are isotopes and relative abundances related?

Catalyst 1. If you have an atom that has 5 protons, 6 neutrons and 5 electrons and an atom that has 6 protons, 6 neutrons, and 5 electrons. Are these elements both isotopes? Why or why not?

Since isotopes occur in different abundances (amounts), how would you find the average atomic mass? From this problem try to come up with a(n) equation(s) for average atomic mass: (L) Naturally occurring chlorine is 75.78% 35 Cl and 24.22% 37 Cl. Calculate the average atomic mass of chlorine.

Calculating Average Atomic Mass In nature, we have various amounts of each isotope of an element Therefore, we use the abundance to get a relative mass

Class Example Naturally occurring chlorine is 75.78% 35 Cl and 24.22% 37 Cl. Calculate the average atomic mass of chlorine.

Table Talk Three isotopes of silicon occur in nature, 92.23% is 28 Si, 4.68% is 29 Si, and 3.09% is 30 Si. Calculate the average atomic mass of silicon.

Stop and Jot Only two isotopes of copper occur naturally 63 Cu accounts for 69.17% and 30.83% is 65 Cu. Calculate the average atomic mass of copper.

Exit slip 1. Sammy says that an isotope of an element is any element with the same number of neutrons, but different number of protons. Is Sammy correct? Why or why not? 2. Naturally occurring chlorine is 75.78% 35 Cl and 24.22% 37 Cl. Calculate the average atomic mass of chlorine.

Catalyst Based on the periodic table: what are the average atomic masses of uranium and plutonium? (L)

LECTURE 10.4– RADIOACTIVE DECAY

Atomic bombs Hiroshima-Little Boy: fission reaction of U-235 Nagasaki-Fat man: fission of Plutonium-239

Based on the pictures, what is radiation?

I. Radioactive Decay Atoms can be unstable and breakdown Radioactive Decay – The spontaneous breakdown of the nucleus into a smaller nucleus, accompanied by the release of particles, radiation, or both.

Chemistry Rap!!! (L) Create and fill out the table as you watch the video with new info you learn about each type of decay Radioactive decay AlphaBetaPositronGamma Symbol

Phet: Online Simulator Google “Alpha decay phet” Download the simulator Complete the simulator handout with your table group, Repeat for “Beta decay phet”

Draw this picture, order the decay types from least harmful to most harmful and explain why.

II. Beta (β) Decay Beta decay converts neutrons to protons and releases an electron (beta particle) neutron  proton + β Electron

III. Gamma (γ) Decay Gamma rays are high energy waves that are released when nucleus goes from high energy state to low energy.

Radiation Summary: Fill in the chart (R) Type of RadiationDescriptionBlocked by? Alpha (α) Beta (β) Gamma (γ) The spitting of a nucleus into a smaller nucleus and______________ Converts a neutron to a proton and ____________________ High energy waves that are released by nucleus

Radiation Summary Type of RadiationDescriptionBlocked by? Alpha (α) Beta (β) Gamma (γ) The spitting of a nucleus into a smaller nucleus and a He atom (alpha particle) Converts a neutron to a proton and an electron (beta particle) High energy waves that are released by nucleus Blocked by paper Blocked by metals Blocked by lead

Class Example Label the following decay as alpha, beta or gamma decay K  Ca + electron

Table Talk Label the following decay as alpha, beta or gamma decay Po  Pb He

Class Example Complete the following reaction if it undergoes beta decay: 14 7 N  ______ + _______

Class Example Complete the following reaction if it undergoes beta decay: 14 6 C  ______ + _______

Exit Slip 2. What is gamma decay? What will stop gamma radiation? 3. What type of decay is shown below: Pa  Ac He

Closing Time Homework 10.3 Final coming up!