ساينس الصف الثاني الاعدادي – الفصل الدراسي الاول ساينس تانية اعدادي – ترم اول In This part we will study : Position of ozone layer – Ozone layer is mainly located at a height 20 : 40 km above sea level . – Ozone layer is located in the lower part of stratosphere layer because : it is the first layer of atmospheric envelope which contains suitable amount of oxygen gas and it faces ultraviolet radiations emitted from the Sun . Structure of ozone layer – Ozone layer is composed of ozone gas (03) which consists of three oxygen atoms . Importance of ozone layer Ozone hole It means thinning or losing parts of ozone layer above the south pole. Pollutants of ozone layer 1. Chlorofluorocarbon compounds (CFC8) : 2. Methyl bromide gas : 3. Halons : 4. Nitrogen oxides : Global warming phenomenon It is the continuous increase in the average temperature of the Earth’s near-surface air. Greenhouse effect: It is the trapping of infrared radiation in the troposphere layer due to the increase in the ratio of greenhouse gases which cause the increase in the planet Earth’s temperature. The negative effects of global warming phenomenon 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