The question asks to identify the planet often referred to as 'Earth's twin' based on similar size and mass. This requires knowledge of the basic characteristics of the planets in our solar system.
The approximate diameter of Earth is \(12,742 \text{ km}\) and its mass is about \(5.97 \times 10^{24} \text{ kg}\). Venus has a diameter of about \(12,104 \text{ km}\) and a mass of about \(4.87 \times 10^{24} \text{ kg}\). These values are remarkably close, hence the term 'Earth's twin'.
D) Venus is often called 'Earth's twin' because it is very similar to Earth in terms of size, mass, and bulk composition. Its diameter is about 95% of Earth's, and its mass is about 80% of Earth's.
The question asks to identify the hottest planet in our solar system. While Mercury is closest to the Sun, its lack of a substantial atmosphere means it cannot retain heat effectively. Venus, despite being farther from the Sun than Mercury, has a dense atmosphere rich in carbon dioxide, which creates a powerful greenhouse effect, trapping heat and making it the hottest planet.
C) Venus — Venus is the hottest planet in the solar system due to its extremely dense atmosphere, predominantly composed of carbon dioxide, which creates a powerful greenhouse effect, trapping heat and leading to surface temperatures of approximately \(462^\circ \text{C}\).
The question asks to identify the two planets in our solar system that exhibit retrograde rotation, meaning they rotate from east to west, which is opposite to the direction of most other planets (west to east).
B) Venus and Uranus are the two planets that rotate from east to west (retrograde rotation), opposite to most other planets.
The question asks about the primary composition of Venus's dense atmosphere. This requires knowledge of planetary science, specifically the atmospheric characteristics of Venus. We need to identify the dominant gas and any significant cloud components.
A) Carbon dioxide with clouds of sulphuric acid. Venus's atmosphere is about 96.5% carbon dioxide, making it the most abundant gas. The thick, opaque clouds that cover the planet are composed mainly of sulphuric acid droplets, which contribute to its high reflectivity and greenhouse effect.
The question asks why Venus appears as the brightest planet from Earth. To answer this, we need to consider factors that affect a planet's apparent brightness, such as its distance from Earth, its size, and its ability to reflect sunlight.
D) It is closer to Earth than any other planet at times and its thick clouds reflect a large fraction of sunlight. This option correctly identifies the two primary reasons for Venus's exceptional brightness: its close proximity to Earth and its high albedo due to its thick, reflective clouds.
The question asks for the Earth's position in terms of its distance from the Sun. To answer this, one needs to recall the order of the planets in our Solar System starting from the Sun.
Therefore, Earth is the third nearest planet to the Sun.
Correct Option: A) Third