A: Copper is classified as a metal on the periodic table and is therefore not classified according to family in the manner that plants and animals are. Copper is red-colored. It is malleable, ductile, and a good conductor of heat and electricity.
For a hard-boiled egg, start the egg in cold water and bring up to the boil. Once the water is gently boiling, set the timer for between 7-10 minutes depending on how well cooked you like your eggs. The longer you boil the egg, the firmer it will be. Once cooked, plunge the hard-boiled egg into plenty of cold water for one minute. Drain and cover with more cold water.
Tips. 1  Extra-large eggs need to cook for slightly longer than large eggs. 2  Add about three minutes to the cooking time, depending how large the egg is. 3  For instance, an extra-large hard-boiled egg might take as long as 15 minutes.