S.8.9.A | TEKS Guide

SCIENCE.8.9.A — Vertical Alignment

Vertical alignment shows student expectations in the same subject area at different grade levels that are related to or build upon one another.

S.8.9.A

describe the life cycle of stars and compare and classify stars using the Hertzsprung-Russell diagram;

ASTRO.13.A

identify the characteristics of main sequence stars, including surface temperature, age, relative size, and composition;

ASTRO.13.B

describe and communicate star formation from nebulae to protostars to the development of main sequence stars;

ASTRO.13.C

evaluate the relationship between mass and fusion on stellar evolution;

ASTRO.13.D

compare how the mass of a main sequence star will determine its end state as a white dwarf, neutron star, or black hole;

ASTRO.13.E

describe the use of spectroscopy in obtaining physical data on celestial objects such as temperature, chemical composition, and relative motion;

ASTRO.13.F

use the Hertzsprung-Russell diagram to classify stars and plot and examine the life cycle of stars from birth to death;

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Recurring themes and concepts — Connections to the content

Recurring themes and concepts provide a connective structure for scientific ideas across disciplines. The connection(s) below show some ways that teachers can help students understand how the content they are learning fits into the broader understanding of science. These connections do not represent all possible connections that might be made but highlight some that are appropriate for this grade level.

Patterns

Patterns are regular sequences that can be found throughout nature.

Depending on the mass of a star, its life cycle will go through a defined pattern. The H-R diagram models the patterns seen in the mass, temperature, absolute magnitude, and luminosity of different classes of stars.

Scale, proportion, and quantity in systems

It is important to consider how changes in scale, proportion, or quantity affect a system’s structure or performance. Scale refers to the size of an object in relation to another object or its environment. Proportion is the ratio of one quantity to another. Quantity is a count of a set of objects or a measurement of a substance.

The H-R diagram compares the temperature, luminosity, absolute magnitude, or mass (quantities) of stars. The proportion of heavier elements increases as a star ages.

Flow of energy and cycling of matter through systems

Matter and energy are conserved, changing forms but maintaining quantities. Energy flows within a system or between systems through transfers and transformations. Matter is cycled within systems through physical and chemical processes.

As stars go through their different life cycles, the flow of energy changes, as seen by the change in color and luminosity. Younger stars produce lighter elements and have different temperatures and colors than older stars which produce heavier elements.

SCIENCE.8.9.A — Vertical Alignment

Recurring themes and concepts — Connections to the content

Cross-curricular Connections