Consider the two 'Postulates' given below.
(ii) There exists at least three points that are not on the same line
Do these postulates contain any undefined terms ? Do they follow from Euclid's postulates ? Explain.

Consider the two 'postulates' gives below: (i) Given any two distinct points A and B, there exists a third point C, which is between A and B. (ii) There exist at least three points that are not on the same line. Do these postulates contain any undefined terms? Are these postulates consistent? Do they follow from Euclid's postulates? Explain.

Consider the two 'Postulates' given below. (i) Given any two distinct points A and B , there exists a third point C , which is between A and B .

Does Euclid's fifth postulate imply the existence of parallel lines? Explain .

Consider the potential energy diagram given below (X) Name the positions A-D (Y) Answer the following quesitons : (i) Both reactoin pathways are : (ii) Which step is the determining step (RDS) ? (iii) Which product is most stable ? (iv) In accordance with Hammonds postulate, exothermic reactions tend to have

a) List any three observation that determine that a chemical reaction has taken place. Also list three in formation that cannot be obtained about a chemical reaction merely by its chemical equation. b) Balance the following chemical equations i) Fe+H_(2)O to Fe_(3)O_(4) +H_(2) ii) CO_(2)+H_(2)O to C_(6)H_(12)O_(6) +O_(2) OR a) Explain the following in terms of gain or lose of oxygen with two examples each. i) Oxidation ii) reduction. b) Balance the following chemical equations. 1) HNO_(3)+Ca(OH)_(2) to Ca(NO_(3))_(2)+H_(2)O ii) NaOH + H_(2)SO_(4) to Na_(2)SO_(4) + H_(2)O

Atoms of eight elements A, B, C, D, E, F, G and H have the same number of electronic shells but different in their outermost shells. It was found that elements A and G combine to form an ionic compound which can also be extracted from sea water. Oxides of the elements A and B are basic in nature while those of E and F are acidic. The oxide of elements D is almost neutral. Answer the following questions based on the information given here in : (i) To which group or period of the periodic table do the listed elements belong ? (ii) Which one of the eight elements is likely to be a noble gas? (iii) Which one of the eight elements would have the largest atomic radius ? (iv) Which two elements amongst these are likely to be the non-metals? (v) Which one of these eight elements is likely to be a semi-metal or metalloid ?