ساينس الصف الثاني الاعدادي – الفصل الدراسي الاول ساينس تانية اعدادي – ترم اول In This part we will study : 4. Thermosphere – It is called the thermal layer because it is the hottest layer of atmospheric envelope . Location – It is the fourth layer of atmospheric envelope . Ionosphere layer Ionosphere layer: It is a layer that contains charged ions and it has an important role in wireless communications. Van-Allen belts They are two magnetic belts surrounding ionosphere and play an important role in scattering harmful charged cosmic radiations. Aurora phenomenon: It is a phenomenon that appears as brightly coloured light curtains seen from both poles (the North and South Poles) of the Earth. Exosphere It is a region in which the atmospheric envelope is inserted in outer space. لمتابعة مستر احمد الباشا وكل ما يخص الساينس : جروب الفيس بوك http://bit.ly/2Of1mcN صفحة الفيس بوك http://bit.ly/2Gq5xMo بالتوفيق مستر احمد الباشا