The chemical compositions of Jupiter and Saturn are most similar to those of a. Uranus and Neptune. b. the terrestrial planets. c. their moons. d. the Sun.

Jupiter and Saturn, two of our solar system's largest planets, are classified as gas giants. These enormous celestial bodies are predominantly composed of gases rather than solid material.
They mainly consist of hydrogen and helium, making them vastly different from smaller, rocky terrestrial planets like Earth or Mars.
The term 'gas giant' underscores their lack of a true solid surface.
Gas giants are known for their thick atmospheres, extensive weather systems, and expansive magnetic fields. Because these planets are composed largely of gases, they have low densities, causing them to be very large in volume but light in weight.
Their atmospheres often feature incredible storms and high-speed winds. Jupiter's Great Red Spot, for example, is a massive storm that has been raging for centuries.
Saturn is famous for its stunning ring system, composed of ice particles, rocky debris, and dust, which revolves around the planet.

Hydrogen and helium are the lightest and most abundant elements in the universe, and they are essential building blocks of gas giants like Jupiter and Saturn.
On these planets, hydrogen and helium are present in both gaseous and metallic forms.
In the outer layers, hydrogen exists mainly as a gas. As one moves deeper into the planet, the pressure increases to such an extent that hydrogen turns into a liquid, and eventually into metallic hydrogen.
This transformation plays a critical role in creating the magnetic fields observed around these planets. Helium, while less abundant than hydrogen, is mixed throughout and contributes to the overall composition and characteristics of the gas giants.
The enormous pressure and temperatures in the core regions of Jupiter and Saturn are thought to create complex forms of these elements, which further influence the planets' magnetic and gravitational fields.

The Sun, which is the central star of our solar system, shares a strikingly similar chemical composition with Jupiter and Saturn.
The primary elements that constitute the Sun are hydrogen and helium. Hydrogen makes up about 74% of its mass, and helium accounts for roughly 24%.
This similarity in composition provides compelling evidence of the common origins of these bodies and the processes that formed our solar system.
In the Sun, hydrogen undergoes nuclear fusion in the core, converting into helium and releasing a vast amount of energy. This process powers the radiant energy and light we receive from the Sun.
The extreme temperatures and pressures in the core of the Sun allow these fusion processes to occur. While Jupiter and Saturn do not undergo fusion, their composition mirrors that of the Sun, demonstrating the chemical uniformity in our solar system's formation.
Understanding the Sun’s composition helps astronomers learn about the life cycles of stars and the evolution of planetary systems.