Which of following are open, close or nearly isolated systéms? i) Human beings, ii). the earth. iii) can of tomato soup iv) ice cube tray filled with water v) coffee in'a thermoflask vi) helium-filled balloon. .

Classify the following as open, closed or isolated system i) A beaker containing open boiling water ii) A chemical reaction in a closed vessel iii) A cup of tea placed on a table iv) Hot water in perfectly insulated closed container

Which of the following statements are true? i) Elements which are least reactive occur in free state or native state ii) Earthly or undesired materials present along with ore are called gangue iii) Among metals, aluminium is the most abundant in the earth crust iv) All ores are minerals but all minerals are not ores v) Gemstone "Ruby" is the impure form of Al_2O_3 containing impurity : Co vi) The set of d-block elements Cu, Ag, Au mostly occur as sulphide ore

Which of the following statements are true? i) Rhamnose and deoxyribose are carbohydrates by their chemical behavior but cannot represented as hydrates of carbon ii) Formaldehyde and acetic acid do not behave like carbohydrate but can be represented by the general formula of carbohydrates, C_x(H_2O)_y iii) Raffinose on hydrolysis gives glucose and galactose only iv) Polysaccharides are also called non-sugars v) In disaccharides, if reducing groups of monosaccharides are bonded, they are non reducing in nature vi) Sorbose is an example of aldose