Question

energy from an atom: flame test
directions: carefully hold the wooden splint into the flame of the bunsen burner, then record the color of the flame in the spaces provided below. the unknowns will be demonstrated by your teacher.

metal	unknown a	unknown b	calcium	potassium	copper	strontium	barium

post - lab questions

1. label the arrows below to explain the change in energy of an electron as it moves from the ground state to an excited state and then back to the ground state.

ground state
excited state
ground state

1. why does an electron return to the ground state after being \excited\?
2. as an electron falls to a lower energy level, it loses energy. where does this lost energy go?
3. in this lab, what caused the electrons to move from the ground state to a higher energy excited state? (where did the energy come from?)

Explanation:

1. When an electron moves from the ground - state to an excited state, it absorbs energy (arrow pointing outward). When it returns from the excited state to the ground state, it emits energy (arrow pointing inward).
2. An electron returns to the ground state because the ground state is the most stable energy state for an electron. Electrons tend to be in the lowest - energy state possible.
3. When an electron falls to a lower energy level, the lost energy is emitted as electromagnetic radiation, such as light.
4. In this lab, the heat energy from the Bunsen burner flame caused the electrons to move from the ground state to a higher - energy excited state.

Answer:

1. Arrow from ground state to excited state: Absorption of energy. Arrow from excited state to ground state: Emission of energy.
2. The ground state is the most stable energy state.
3. Emitted as electromagnetic radiation (light).
4. Heat energy from the Bunsen burner flame.