The nearest star to our sun is Proxima Centauri, at a distance of 4.3 light-years from the sun. A light-year is the distance that light travels in one year (365 days). How far away, in km, is Proxima Centauri from the sun?

Name: Chemistry: A Molecular Approach
Author: Tro
ISBN: 9780134112831

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Understand that a light-year is the distance light travels in one year.

Use the speed of light, which is approximately 299,792 kilometers per second.

Calculate the number of seconds in one year: 365 days/year * 24 hours/day * 60 minutes/hour * 60 seconds/minute.

Multiply the number of seconds in a year by the speed of light to find the distance light travels in one year (1 light-year).

Multiply the distance of 1 light-year by 4.3 to find the distance to Proxima Centauri in kilometers.

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Light-Year

A light-year is a unit of distance that represents how far light travels in one year. Since light moves at a speed of approximately 299,792 kilometers per second, a light-year is equivalent to about 9.46 trillion kilometers. This concept is essential for understanding astronomical distances, as it allows us to express vast spaces in manageable terms.

Distance Calculation

To find the distance to Proxima Centauri in kilometers, one must convert light-years to kilometers. This involves multiplying the number of light-years (4.3) by the number of kilometers in one light-year (approximately 9.46 trillion). Mastery of unit conversion is crucial in chemistry and physics for accurately interpreting and solving problems involving different measurement systems.

Astronomical Units

Astronomical units (AU) are another way to measure distances in space, where 1 AU is the average distance from the Earth to the Sun, approximately 149.6 million kilometers. While light-years are often used for interstellar distances, understanding AU helps contextualize distances within our solar system. This knowledge is beneficial for comparing distances between celestial bodies.

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