Life Cycle of a Star online exercise for - Free Printable

The task involves arranging the stages of the life cycle of a star in the correct order. The provided image shows some stages, such as "Nebula" and "Planetary nebula," but the rest need to be filled in. Below is the explanation and solution:

Life Cycle of a Star

The life cycle of a star generally progresses through the following stages (for a medium-sized star like our Sun):

1. Nebula: A vast cloud of gas and dust where stars are born.
2. Protostar: A dense region within a nebula that begins to collapse under its own gravity, forming a protostar.
3. Main Sequence Star: Once the protostar ignites nuclear fusion in its core, it becomes a main sequence star, burning hydrogen into helium.
4. Red Giant: As the star exhausts its hydrogen fuel, it expands and cools, becoming a red giant.
5. Planetary Nebula: After shedding its outer layers, the star leaves behind a glowing shell of gas called a planetary nebula.
6. White Dwarf: The core of the star collapses into a small, dense white dwarf, which gradually cools over time.

Solution

Based on the provided image and the typical life cycle of a star, the stages should be arranged as follows:

1. Nebula → Protostar → Main Sequence Star → Red Giant → Planetary Nebula → White Dwarf

Explanation of Each Stage

1. Nebula: This is the starting point, where a massive cloud of gas and dust exists in space.
2. Protostar: Gravity causes the nebula to collapse, forming a dense region that heats up and becomes a protostar.
3. Main Sequence Star: Nuclear fusion begins in the core, converting hydrogen into helium, and the star stabilizes as a main sequence star.
4. Red Giant: When the star runs out of hydrogen fuel in its core, it expands and cools, becoming a red giant.
5. Planetary Nebula: The outer layers of the red giant are ejected, creating a glowing shell of gas around the remaining core.
6. White Dwarf: The core of the star collapses into a dense white dwarf, which slowly cools over billions of years.

Final Answer

The completed diagram should look like this:

```
Nebula → Protostar → Main Sequence Star → Red Giant → Planetary Nebula → White Dwarf
```

So, the boxes should be filled in the following order:
- First box: Protostar
- Second box: Main Sequence Star
- Third box: Red Giant
- Fourth box: Planetary Nebula
- Fifth box: White Dwarf

Final Answer:
\boxed{\text{Protostar, Main Sequence Star, Red Giant, Planetary Nebula, White Dwarf}}