Hydrargyrum medium-arc iodide

Hydrargyrum medium-arc iodide is a really fancy way of saying a special kind of light bulb. It's not like your regular light bulb at home, because it uses special gases and chemicals inside of it to make the light that comes out.

The first part of the name, "hydrargyrum," is just a really hard word for "mercury." You might have heard of mercury before: it's a shiny silver liquid that's sometimes used in thermometers. In this special light bulb, there's a tiny bit of mercury gas that helps make the light.

The second part of the name, "medium-arc," is talking about how the light bulb is shaped. It has a tiny tube inside of it that makes a curved line, and the light comes out of that. This shape helps the electricity move through the gases and chemicals better, which makes the light stronger and brighter.

Finally, the last part of the name, "iodide," is a fancy way of saying that iodine gas is also added to the mix. Iodine is a chemical element that you might have learned about in science class, and it helps to make the light look more natural and pleasant to your eyes.

So all of that together means that a hydrargyrum medium-arc iodide light bulb is a special kind of light that's made from mercury, has a curved shape inside, and uses iodine gas to make the light look good. Cool, huh?