Objectives Students will demonstrate mastery of the formation of stars, planets and galaxies by developing a 3-chapter children’s book. Mastery Level: 70% of students will earn 195/325 point on the Formation of Stars, Planets and Galaxies Children’s Book Students will become familiar with the patterns of organization in the Periodic Table of Elements by taking notes, analyzing an actual PTE and answering an exit ticket question. Mastery Level: 70% of students can satisfactorily answer the exit ticket question Students will know how to identify elements based on their electromagnetic radiation light emission by taking notes and answering an exit ticket question. Mastery Level: 70% of students can satisfactorily answer the exit ticket question

Homework – COPY! Each student will research the following information for the first 6 elements (H – C): The symbol for the element The atomic number for the element Group number the element is located The period the element is located on Draw the light emission spectrum for that element

Engage What is the PTE? How do you think the PTE is organized? How do scientists know what elements are found in the universe when humans have never been beyond the moon?

Explore Students will read the article “Elements as Building Blocks”. Students annotate the article using the close read annotations posted on classroom charts and will use their annotations to write a 3-5 sentence summary. After the students write their summaries, students will write their findings on chart paper. Source: http://www.chem4kids.com/files/elem_pertable.html

Explain Light Emissions PPT Show the students the first twenty elements’ light emission Source: http://chemistry.bd.psu.edu/jircitano/periodic4.html

Light and Electronic Transitions

The Big Questions What is light? How is light emitted? What do electrons have to do with light? What are emission spectra? How do flame tests help identify metals?

The Electromagnetic Spectrum All light is part of the EM spectrum. Most is invisible: gamma, X-rays, UV, IR, microwaves, radio waves Visible light: wavelength (w.l.) from 400 to 700 nm.

The EM Spectrum

EM Radiation Light is a carrier of energy. Energy is proportional to frequency. Frequency is inversely proportional to wavelength. Longer wavelength = lower frequency = lower energy. Shorter wavelength = higher frequency = greater energy.

Electrons and Quanta Ground state – the lowest energy position an e- can occupy. Excited state – a temporary high-energy position. Quantum (pl. quanta) – the amount of energy needed to move an e- to a higher energy level.

Electrons and Quanta If an atom absorbs exactly 1 quantum of energy, an electron can be boosted from a ground state to an excited state. The electron is only in the excited state for a very short period of time. Soon the e- returns to its ground state and emits the quantum of energy as light. In some cases the emitted light is in the visible spectrum.

Light and Electrons Excited state (E.S.) electron 1 quantum Ground state (G.S.) electron

Light and Electrons Excited state (E.S.) electron 1 quantum Ground state (G.S.) electron Excited state (E.S.) electron 1 quantum

Light and Electrons

Emission Spectrum Emission spectrum – wavelengths of light given off by an element when it is excited (usu. by heat). Every element has unique emission spectrum.

Emission Spectra Hydrogen Helium Carbon

Flame Tests Flame test – used to ID some metals in compounds. Each metal gives a flame a characteristic color. Can identify metals based on flame colors.

Evaluate Exit Ticket Questions: How is the Periodic Table of Elements organized? What information can you obtain from the Periodic Table of Elements? What is light emission and what is it used for?