Emission nebulae are also called ________ because they are composed of ionized hydrogen.
A)HI regions
B)HII regions
C)Bok globules
D)HeI regions
E)reflection nebulae

Question

Quizplus · Accepted Answer

Emission nebulae are composed of ionized hydrogen, which is also called HII (pronounced H-two) regions. HI (pronounced H-one) regions are neutral hydrogen clouds that have not been ionized. Bok globules are dark clouds of gas and dust, HeI (pronounced He-one) is singly ionized helium, and reflection nebulae are composed of dust that reflects the light of nearby stars.

Emission Nebulae Are Also Called ________ Because They Are Composed