Everyday Science

Sunlight is composed of seven colors, which are red, orange, yellow, green, blue, indigo, and violet. These seven colors together form the visible spectrum of light.

Sunlight helps the skin produce vitamin D, which is essential for bone health and immune function. It is not a source of vitamins C, E, or K.

Elements are pure substances made up of only one type of atom. Therefore, elements are made of atoms, not molecules, compounds, or specific substances like H2O.

Samuel Morse developed the telegraph code, known as Morse code, which was used to transmit messages over telegraph lines.

Sound requires a medium (solid, liquid, or gas) to travel because it propagates through vibrations of particles. A vacuum lacks particles, so sound cannot travel through it.

A rainbow is typically observed when the sun is less than about 42 degrees above the horizon because the angle of light refraction and reflection inside water droplets creates the rainbow at an angle of approximately 40-42 degrees from the antisolar point. Therefore, the sun must be at an angle around 40 degrees above the horizon to see a rainbow.

Rudolf Diesel invented the diesel engine in 1897, making option D the correct answer. The other options are unrelated to the invention of the diesel engine.

All matter is composed of atoms, which are the basic building blocks of all substances. Air and water are forms of matter made up of atoms, while vibrations are not matter themselves.

Walter Hunt invented the safety pin in 1849. He created it as a simple fastening device with a spring mechanism and a clasp to cover the sharp point, making it safe to use.

Protons are subatomic particles with a positive charge, whereas electrons are negatively charged and neutrons have no charge. Therefore, protons are the positively charged particles.