IELTS Advantage Practice Reading Test 1 - Passage 1 - The Layers of the Sun

Sep 30, 2026

Practice reading passage explaining how the sun’s mass distribution works and how its structure is organized into distinct layers. It describes the core where nuclear fusion combines hydrogen into helium, the radiative zone where photons move outward extremely slowly, and the convection zone that drives solar activity such as flares and sunspots. It also covers the photosphere, chromosphere, and corona, including their temperatures, appearance, and roles in emitting light and ultraviolet effects.

LanguageEnglish

CategoryExam

FormatPDF

Pages13

Reading Time33 min

AccessFree to download

Passage 1

The Layers of the Sun

Questions 1-4

IELTS Advantage Practice Reading Test 1 Passage 1 The Layers of the Sun Consider the earth, the moon, and all the other planets in our solar system. Think about the mass that all those objects must have when they are all added together. Counter-intuitively, added alltogether they account for only 0 . 2% of the total mass of the solar system. The sun makes up the remaining 99.8% of all the mass in the solar system! The sun is the center of the solar system and the largest object in the solar system. Our sun is a star that provides light and heat and supports almost all life on Earth. The sun is a sphere, but unlike the earth and the moon, it is not solid. Most atoms in the sun exist as plasma, or a fourth state of matter made up of superheated gas with an electrical charge. Our sun consists almost entirely of the elements hydrogen and helium, and because the sun is not solid, it does not have a defined outer boundary. It does, however, have a definite internal structure. There are several identifiable layers of the sun: The core is the innermost or central layer of the sun. The core is plasma, but moves similarly to a gas. Its temperature is around 27 million degrees Celsius. In the core, nuclear reactions combine hydrogen atoms to form helium, releasing vast amounts of energy in the process. The energy released then begins to move outward, towards the outer layers of the sun. Just outside the core is the radiative zone, which has a temperature of about 7 million degrees Celsius. The energy released in the core travels extremely slowly through the radiative zone. Particles of light called photons can only travel a few millimeters before they hit another particle in the sun, are absorbed and then released again. It can take a photon as long as 50 million years to travel all the way through the radiative zone. Surrounding the radiative zone is the convection zone. Here, hot material from near the sun's center rises, cools at the surface, and then plunges back downward to receive more heat from the radiative zone. This movement helps to create solar flares and sunspots. These first three layers make up what we would actually call "the sun" . The next three layers make up the sun's atmosphere. Of course, there are no solid layers to any part of the sun, so these boundaries are fuzzy and indistinct. The visible surface of the sun is known as the photosphere. This is the region of the sun that emits sunlight. It's also one of the coolest layers of the sun—only about 6700°C. Looking at a photograph of the sun's surface, you can see that it has several different colors: oranges, yellow and reds, giving it a grainy appearance. We cannot see this when we glance quickly at the sun as our eyes can't focus that quickly and the sun is too bright for us to look at for more than a brief moment. Looking at the sun for any length of time can cause blindness, so don't try it! Sunlight is emitted from the sun's photosphere. A fraction of the light that travels from the sun reaches Earth. It travels as light in a range of wavelengths, including visible light, ultraviolet, and infrared radiation. Visible light is all the light we can see with our eyes. We can't see ultraviolet or infrared radiation, but their effects can Note: This is not a real IELTS test. This practice test is to give you an opportunity to practise implementing the strategies from the course. It does not reflect the scores, time needed or level of difficulty of a real IELTS test. IELTS Advantage Practice Reading Test 1 still be detected. For example, sunburn is caused by ultraviolet radiation when you spend too much time in the sun. The chromosphere is the zone about 2,000 kilometers thick that lies directly above the photosphere. The chromosphere is a thin region of the sun's atmosphere that glows red as it is heated by energy from the photosphere. Temperatures in the chromosphere range from about 4000°C to about 10,000°C. Jets of gas fire up through the

FAQs

What are the main layers of the sun described in the passage?

The passage describes the core, radiative zone, convection zone, then the sun’s atmosphere layers: photosphere, chromosphere, and corona.

How does energy move from the sun’s core to the outer layers?

Energy released in the core travels outward; in the radiative zone it moves extremely slowly because photons are absorbed and re-emitted repeatedly.

Why are the boundaries between the sun’s layers described as unclear?

Because the sun has no solid layers, the boundaries between layers are fuzzy and indistinct.

Sep 30, 2026

Uploaded by Lucas Martin