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.
Astronomers define star brightness in terms of apparent magnitude (how bright the star appears from Earth) and absolute magnitude (how bright the star appears at a standard distance of 32.6 light years, or 10 parsecs).Astronomers also measure luminosity â the amount of energy (light) that a star emits from its surface.stronomers define star brightness in terms of apparent magnitude (how bright the star appears from Earth) and absolute magnitude (how bright the star appears at a standard distance of 32.6 light years, or 10 parsecs).