Answer:
B. contain hydrogen
C. clouds of gas and dust
E. needed to create a star
Explanation:
A star is a giant astronomical or celestial object that is comprised of a luminous sphere of plasma, binded together by its own gravitational force.
Some of the examples of stars are; Vega, Sun (closest to planet Earth), Antares, Betelgeus, Canopus, etc.
Stars are typically made up of two (2) main hot gas, Hydrogen (H) and Helium (He). The chronological order in which the formation of a star occur are;
1. Gravity pulls gas and dust together to form dense cores.
2. A protostar forms as mass increases.
3. Nuclear fusion begins under high pressure.
Scientists have been able to understand and discover that, gravity pulled materials (low-density cloud of interstellar gas and dust known as a nebula) together forming the planetary bodies in our solar system.
A dark nebula can be defined as an interstellar cloud that is so dense as a result of high concentration of gas and dust and as such it obscures the visible wavelengths of light from stars behind it, thus appearing completely opaque (dark patch) in front of a bright emission nebula or in regions having plenty stars.
The characteristics of a nebulae are;
I. It contain hydrogen.
II. Clouds of gas and dust
III. It is needed to create a star.