Everyday Science

Helium was first discovered in the solar spectrum during a total solar eclipse in 1868, about 151 years ago, by astronomers analyzing the sun's light. This discovery was the first identification of an element outside Earth.

Convex mirrors are used in automobiles because they provide a wider field of view, allowing drivers to see more area behind and beside the vehicle, which enhances safety.

The length of a year is determined by the time a planet takes to complete one orbit around the Sun. Among the given options, Mercury has the shortest year (88 Earth days), Earth has a year of 365 days, Mars has a year of 687 days, and Jupiter has the longest year, taking about 4,333 Earth days (approximately 11.86 Earth years) to complete one orbit around the Sun. Therefore, the correct answer is Jupiter (A).

Diabetes is primarily caused by a lack of insulin or the body's inability to use insulin effectively. Insulin is a hormone that regulates blood sugar levels, so its deficiency leads to diabetes.

The central color of a rainbow is green, which appears in the middle of the visible spectrum between blue and yellow. This is why green is considered the central color in the sequence of rainbow colors.

A lunar eclipse occurs when the Earth is positioned between the Sun and the Moon, causing the Earth's shadow to fall on the Moon. This alignment blocks sunlight from directly reaching the Moon.

Venus is the brightest planet visible from Earth due to its thick clouds reflecting sunlight, making it appear brighter than all other planets in the night sky.

Venus is often called Earth's sister planet because of its similar size, mass, and proximity to the Sun compared to Earth.

The approximate age of the Sun is about 4.6 billion years, based on radiometric dating of meteorites and models of solar system formation.

The 'bar' is a unit of pressure, commonly used to measure atmospheric pressure. It is not a unit of temperature, heat, or electric current.