Question

life cycle of the sun
scientists believe that our sun, like other stars, started out as a big ball of dust and hydrogen. as
the dust and gas condensed or pulled together, it formed a dense ball of matter. the amount of
matter is enough to create high temperature and pressure. this causes hydrogen atoms to fuse
together in a nuclear fusion reaction. this reaction produces helium atoms and releases
tremendous amounts of energy. this energy travels through space as light and thermal energy.

throughout most of the life of a star, the fuel for its energy is hydrogen that was present when the
star was born. in the star’s early life, it gets hotter and hotter until most of the hydrogen is used
up. the star then cools and expands into a red giant. after this, the star collapses and starts a
fusion reaction using helium as a fuel to create carbon. a star in this stage is called a white dwarf.

the diagram shown below represents the life cycle of the sun

an incomplete statement that explains how energy is transferred from the interior of the sun to earth is
shown below. drag and drop words into each box to explain how energy is generated by the sun and
transferred from the sun to earth. the words may be used more than once or not at all.

the sun generates □ through the process of □. the □
then travel to earth through the process of □

■ hydrogen atoms ■ radiation ■ convection ■ heat and light ■ nuclear fusion

Explanation:

1. The Sun generates energy in the form of heat and light through nuclear fusion (where hydrogen atoms fuse).
2. The first blank: The Sun's energy output is heat and light, so "heat and light".
3. Second blank: The process that generates Sun's energy is nuclear fusion (hydrogen fuses), so "nuclear fusion".
4. Third blank: The energy (heat and light) travels as radiation? Wait, no—wait, the energy generated is heat and light, then the energy (heat and light) travels via radiation? Wait, let's re - read. The Sun generates [heat and light] through [nuclear fusion]. Then the [heat and light] travels to Earth through [radiation]? Wait, no, the options: hydrogen atoms, radiation, convection, heat and light, nuclear fusion. Let's parse:

First box: What does the Sun generate? The text says "releases tremendous amounts of energy" which is heat and light. So first box: heat and light.

Second box: The process to generate it? Nuclear fusion (hydrogen fuses). So second box: nuclear fusion.

Third box: What travels to Earth? The heat and light (the energy). So third box: heat and light? Wait, no, wait the sentence: "The Sun generates [x] through the process of [y]. The [z] then travel to Earth through the process of [w]."

Wait, x: energy (heat and light). y: nuclear fusion. z: the energy (heat and light). w: radiation (since energy from Sun to Earth is via electromagnetic radiation, not convection (convection is in fluids) or hydrogen atoms (hydrogen is fused, not traveling as is)).

Wait, let's check the options:

Options: hydrogen atoms, radiation, convection, heat and light, nuclear fusion.

So:

1. The Sun generates heat and light through the process of nuclear fusion. The heat and light then travel to Earth through the process of radiation.

Wait, but let's confirm with the text: "This energy travels through space as light and thermal energy" — energy is heat and light, and the way it travels through space (vacuum) is radiation (since convection needs a medium, conduction too; radiation is electromagnetic, no medium needed).

So:

First blank: heat and light

Second blank: nuclear fusion

Third blank: heat and light (the energy that travels)

Fourth blank: radiation

Wait, but let's check the sentence structure: "The Sun generates [blank1] through the process of [blank2]. The [blank3] then travel to Earth through the process of [blank4]."

So blank1: heat and light (what the Sun generates)

blank2: nuclear fusion (process to generate it)

blank3: heat and light (the generated energy that travels)

blank4: radiation (process of travel through space)

Yes, that makes sense.

Answer:

First box: heat and light; Second box: nuclear fusion; Third box: heat and light; Fourth box: radiation