ساينس الصف السادس الإبتدئي الفصل الدراسي الاول ساينس سادسة ابتدائي – ترم أول In This part we will study : Preparation of Oxygen: – Oxygen is prepared in laboratory by the decomposition of Hydrogen Peroxide to release Oxygen gas in the presence of Manganese dioxide. – Oxygen gas occupies one fifth of the air volume. Conclusion: -Hydrogen peroxide dissociates (decomposes) in presence of manganese dioxide into water and oxygen gas. Explanation: Oxygen gas replaces water in the cylinder and is collected at the top of the cylinder; this is called downward displacement of water. 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