Titanium is a chemical element with symbol Ti and atomic number 22. It is a lustrous transition metal with a silver color, low density and high strength. It is highly resistant to corrosion in sea water, aqua regia, and chlorine.
Titanium foil has also been used in making of the camera shutters, a most unseen and unknown device hidden inside a camera that allows light to pass for a short period of time, for the purpose of exposing film or an electronic sensor to light to make a photo.