Zinc is a bluish-white, moderately hard metal. It is brittle at room temperature and at temperatures above 150Â°C, being workable only in the range between 100Â°C and 150Â°C.It is an active metal and will displace hydrogen even from dilute acids.The principal use of zinc is for the galvanizing of iron sheets or wires.inc is a bluish-white, moderately hard metal. It is brittle at room temperature and at temperatures above 150Â°C, being workable only in the range between 100Â°C and 150Â°C. It is an active metal and will displace hydrogen even from dilute acids. The principal use of zinc is for the galvanizing of iron sheets or wires.
Cooler stars emit much of their light in the red part of the spectrum, so you see them as red. Somewhat hotter stars, like our Sun, emit much of their light in the green (or yellow), with smaller amounts of red and blue. This balance of colors your eye sees as white.
Stars have a wide range of apparent brightness measured here on Earth. The variation in their brightness is caused by both variations in their luminosity and variations in their distance. An intrinsically faint, nearby star can appear to be just as bright to us on Earth as an intrinsically luminous, distant star.