What are the various components present in the the atmosphere?
Name five elements and five compound those exist as gases at room temperature.

What are the various components present in the atmosphere?

A scientist studying reactions of metals and non-metals. He knew group 1 and 2 elements are metals while group 17 elements are non-metals. So, he chooses different elements from group 1 and 2 and group17 Name the element in group 17 which forms a diatomic molecule and exists in solid state at room temperature .

Mendeleev predicted the existence of certain elements not know at that time. He named two of these elements as eka-aluminium and eka-silicon. a. Name the elements which have taken the place of these elements. b. Mention the group and period of these elements in the modern periodic table. c. Which one of these two elements is a metalloid? d. How many valence electrons are present in eka-silicon? e. Eka-aluminium forms a chloride. What is its formula?

Read the paragraph and answer the questions given below : Our atmosphere is getting hotter. more turbulent, and more unpredictable because of the “boiling and churning” effect caused by the heat-trapping greenhouse gases within the upper layers of atmosphere. With increase of carbon, methane, or other greenhouse gas levels in the atmosphere, our local weather and global climate is further agitated, heated, and “boiled”. The green house gases such as water vapour, carbon dioxide, methane, nitrous oxide, and ozone are causing great impact on life on earth. Due to global warming, the glaciers are melting, causing sea level rise, coastal submergence and frequent natural disasters. We have to rethink while taking the development projects and help to protect the existing life forms on the earth before its too late because climate change can exterminate us. What is the chain of impacts caused due to global warming ?

Name the method that is used for the separation of invidual components having different solubilities at the same temperature from a mixture of water soluble salts , present in aqueous solutions .

A compound made of elements C and D crystallizes in fcc structure. Atoms of C are present at the corners of the cube. Atoms of D are at the centres of faces of the cube. What is the formula of the compound?

Read the paragraph and answer the questions given below : Our atmosphere is getting hotter. more turbulent, and more unpredictable because of the “boiling and churning” effect caused by the heat-trapping greenhouse gases within the upper layers of atmosphere. With increase of carbon, methane, or other greenhouse gas levels in the atmosphere, our local weather and global climate is further agitated, heated, and “boiled”. The green house gases such as water vapour, carbon dioxide, methane, nitrous oxide, and ozone are causing great impact on life on earth. Due to global warming, the glaciers are melting, causing sea level rise, coastal submergence and frequent natural disasters. We have to rethink while taking the development projects and help to protect the existing life forms on the earth before its too late because climate change can exterminate us. What can we do to reverse effects climate change?

What is cancer? Differentiate between benign tumor and malignant tumor. Name the main five types of cancer.