The chemical reaction for CFC is: CCl3F = CCl2F + Cl. Uses. Due to their chemical properties, CFCs became useful as coolants and propellants. More commonly known as freon for refrigeration, CFCs are used extensively in appliances as a safe method of refrigeration. The other main use for CFCs has been as a propellant for aerosol cans.
The earliest known Egyptian pyramids are found at Saqqara, northwest of Memphis. The earliest among these is the Pyramid of Djoser (constructed 2630 BCâ2611 BC) which was built during the third dynasty. This pyramid and its surrounding complex were designed by the architect Imhotep, and are generally considered to be the world's oldest monumental structures constructed of dressed masonry.
The three main pyramids are-The Pyramid of Khufu. The Pyramid of Khafre. The Pyramid of Menkaure. Plus eight much smaller satellite pyramids. The plains of Giza are dominat â¦ ed by three pyramids, which were built by the pharaohs Khufu, Khafre, and Menkaure about 4,500 years ago.The Great Pyramid, built by Khufu, is approximately 482 feet tall, and the base is immense-each side is 756 feet long. It took more than twenty years to construct.he Pyramid of Khufu also known as The Great Pyramid of Giza and the Pyramid of Cheops [his Greek name] The Pyramid of Khafre is also known as the centre pyramid.