Question

Which of the following important components does a planetary nebula contribute to the interstellar medium?

A) molecules such as NH3 and CH4, which contribute to giant molecular clouds
B) UV light that photoionizes hydrogen. The hydrogen, on recombination, produces the red Balmer- light by which we see interstellar emission nebulae.
C) rotational motion from the original star, which serves to concentrate interstellar matter into new stars and planetary systems
D) nuclei of moderately heavy elements, major components of planets such as our own

Answer 1

The key contribution of a planetary nebula to the interstellar medium is the release of nuclei of moderately heavy elements which are critical components of planets like our own. The correct option is (D).

Step-by-step explanation:

A planetary nebula contributes several components to the interstellar medium following the death of a medium-sized old star. When considering the options provided, the most significant contribution of a planetary nebula is d) nuclei of moderately heavy elements, which are major components of planets similar to Earth. These elements are produced during the lifetime of the star and released into the space, enriching the interstellar medium and contributing to the material from which new stars and planetary systems are formed.

The planetary nebula does not primarily contribute molecules like NH3 and CH4; these are more commonly found in giant molecular clouds. UV light photoionizes hydrogen in other types of nebulae, leading to H II regions, but this process is not a direct contribution of a planetary nebula. As for rotational motion, it isn't a physical material or element that can be contributed to the interstellar medium by a planetary nebula.