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.
A convection oven circulates hot air with a fan. Unlike conventional radiant (also called thermal) ovens, convection ovens have a fan that continuously circulates air through the oven cavity. When hot air is blowing onto food, as opposed to merely surrounding it, the food tends to cook more quickly.