BHS Earth Science Guide

Stars

Earth Science

Quarter 1

McGraw Hill Module 23

● Evidence could include:

○ Observations of star cycles in medium and small stars ○ Nuclear fusion processes occurring on Earth

Relationships Students identify the following relationships between components of the given model: ● The production of energy by the process of fusion. ● The description of the process of radiation (energy transfer) and the components involved ● How energy released from the Sun reaches Earth’s systems Connections Students use the model to: ● Predict how the relative proportions of hydrogen to helium change as the sun ages. ● Qualitatively describe the scale of the energy released by the fusion process as being much larger than the scale of the energy released by chemical processes. ● Explicitly identify that chemical processes are unable to produce the amount of energy fowing out of the sun over long periods of time, thus requiring fusion processes as the mechanism for energy release in the sun. Students construct an explanation that includes: ● A summary of the process of nuclear fusion. ● An explanation of the relationship between nuclear fusion and radiation. ● Observations of the lifespan of stars the same size as our Sun. Evidence Students identify and describe the evidence to construct the explanation, including: ● Chemical processes on Earth do not generate enough energy to explain the Sun’s energy but nuclear processes on Earth do. ● The process of radiation can transfer energy from the sun through the vacuum of space. ● The Sun is the same size as many other medium sized stars and will meet the same fate as they have. Students use a variety of valid and reliable sources for evidence, which may include theories, simulations, peer review, and students’ own investigations. Reasoning ● All fuels will eventually run out, so the Sun will run out of fuel but not for several billion years. ● There is no air in space to connect the Sun’s energy with Earth through conduction or convention, it must be radiation. ● Nuclear bombs on Earth release enormous amounts of energy from a small amount of mass. Standard 1.3 Develop a model based on evidence to illustrate the life span of the Sun and the role of nuclear fusion that includes: ● Hydrogen as the sun’s fuel

● Helium and energy as the products of fusion processes in the sun, ● The sun, like all stars, has a life span based primarily on its initial mass, ● The sun’s lifespan is about 10 billion years.