Earthâs crust is made of rock, and rock is made of natural substances called MINERALS. There are three main types of rockâsedimentary, igneous, and metamorphic rock. Each type is produced in different ways.The oldest rocks on Earth were formed about 3.8 billion years ago.arthâs crust is made of rock, and rock is made of natural substances called MINERALS. There are three main types of rockâsedimentary, igneous, and metamorphic rock. Each type is produced in different ways.
The first step to energy efficiency in your kitchen is to consider your appliances, and appliances with the ENERGY STARÂ® seal of approval are always the most energy efficient. Convection ovens also make a difference. The heated air is continuously circulated which reduces cook times as well as the temperatures required. On average you'll use 20% less energy a month running your convection oven, as compared to a standard oven.
Convection ovens circulate hot air through the cooking chamber, decreasing the baking time required. Most recipes specify cooking times for conventional ovens; using a convection oven means you need to alter both the cooking time and temperature in conventional recipes to prevent burning or overcooking your food.sing a baking sheet or pan with shorter walls allows the hot air from the convection oven to come into more contact with the food, allowing for more even cooking. Tara Novak/Demand Media. Place the food in the oven and decrease the cooking time by 25 percent.