Answer: B) 2 Explanation: The number of bonds between a pair of atoms is called the bond order. Bond orders can be calculated from Lewis structures, which are the heart of the valence-bond model. Oxygen, for example, has a bond order of two. When there is more than one Lewis structure for a molecule, the bond order is an average of these structures. The bond order in sulfur dioxide, for example, is 1.5  the average of an S-O single bond in one Lewis structure and an S=O double bond in the other. In molecular orbital theory, we calculate bond orders by assuming that two electrons in a bonding molecular orbital contribute one net bond and that two electrons in an antibonding molecular orbital cancel the effect of one bond. We can calculate the bond order in the O2 molecule by noting that there are eight valence electrons in bonding molecular orbitals and four valence electrons in antibonding molecular orbitals in the electron configuration of this molecule. Thus, the bond order is two.

In chemistry rusting is called as oxidation. Oxidation is a chemical process where metal gains oxygen and become oxide. In rusting the Iron ore make a chemical reaction with the oxygen in the presence of water and environmental or atmospheric moisture to produce an Iron oxide. Iron oxide is otherwise called as rust. The rusting of iron is a chemical change because it is two substances reacting together to make a new substance.    Rusting would only be a physical change if iron molecules remained pure iron throughout the process.

Answer: B) ASCII text Explanation: Word and WordPad can save documents as ASCII text and HTML, but this approach can lead to problems. NotePad should launch with a new document open. From the File pull-down menu, Select "Save As," save the file to the Desktop, and name the file using the ".html" extension (e.g., "home.html").

Answer: C) 81 Explanation: 729 = 9 x 9 x 9 => Cube root of 729 = 9   Now, required square of 9 = 9 x 9 = 81.

Answer: B) Magnify Explanation: As Microphone makes sound louder similarly Microscope makes the object magnified.   Hence, Microphone : Loud :: Microscope : Magnify.

Answer: C) Rs. 9000 Explanation: Let Rs. K invested in each scheme Two years C.I on 20% = 20 + 20 + 20x20/100 = 44% Two years C.I on 15% = 15 + 15 + 15x15/100 = 32.25% Now, (P x 44/100) - (P x 32.25/100) = 528.75 => 11.75 P = 52875 => P = Rs. 4500   Hence, total invested money = P + P = 4500 + 4500 = Rs. 9000.

Answer: B) Chennai or Madras Explanation: Chennai port is known for its Coastal breakwater, artificial, large seaport type of harbor. Chennai Port, formerly known as Madras Port, is the second largest container port of India, behind the Nhava Sheva Port, and the largest port in the Bay of Bengal. It is the third oldest port among the 13 major ports of India

Answer: C) 90 Explanation: The given number series follows a pattern that, 56 56 + 8 = 64 64 - 16 = 48 48 + 32 = 80 (Not equal to 90) 80 - 64 = 16 16 + 128 = 144    Hence, the odd number in the given number series is 90.