If the diameter of a carbon atom is 0.15 nm, calculate the number of carbon atoms which can be placed side by side in a straight line across length of scale of length 20 cm long.

The diameter of zinc atom is 2.7A^@ . Calculate number of atoms present in a length of 1.6 cm of the zinc are arranged side by side lengthwise.

2 xx 10^8 atoms of carbon are arranged side by side. Calculate the radius of carbon atom if the length of this arrangement is 2.4 cm.

Calculate the numbe rof atoms present in 2 grams of crystal which his face centred cubic lattice having edge length of 100 pm and density 10g cm_3

A domain in ferromagnetic iron is in the form of a cube of side length 1 xx 10^-6 m . Estimate the number of iron atoms in the domain, the maximum possible dipole moment and magnetization of the domain. Given: density 7.9frac(g)(cm^3) , molecular mass of iron = 55 g/ mole. Assume each atom has a dipole moment of 9.27 xx 10^-24 Am^2 .

In an experiment, DNA is treated with a compound which tends to place itself amongst the stacks of nitrogenous base pairs. As a result of this, the distance between two consecutive base increases. from 0.34nm to 0.44 nm. Calculate the length of DNA double helix (which has 2 × 10 9 bp) in the presence of saturation amount of this compound

Carbon forms a large number of compounds because of its two unique properties formed many have long straight chains of carbon, branched chains of carbon or rings of carbon. In these compounds, carbon atoms may form single, double or triple covalent bonds. Compounds in which the carbon atoms are linked to each other by single bonds are called saturated carbon compounds whereas compounds having at least one carbon-carbon double or triple bond are called unsaturated carbon compounds. Compounds containing only carbon and hydrogen are known as hydrocarbons. Based on the above information, answer the following questions. ii. Give two examples of carbon compounds which have ring structure.

Carbon forms a large number of compounds because of its two unique properties formed many have long straight chains of carbon, branched chains of carbon or rings of carbon. In these compounds, carbon atoms may form single, double or triple covalent bonds. Compounds in which the carbon atoms are linked to each other by single bonds are called saturated carbon compounds whereas compounds having at least one carbon-carbon double or triple bond are called unsaturated carbon compounds. Compounds containing only carbon and hydrogen are known as hydrocarbons. Based on the above information, answer the following questions. iii. What are saturated hydrocarbons? Give one example.

Carbon forms a large number of compounds because of its two unique properties formed many have long straight chains of carbon, branched chains of carbon or rings of carbon. In these compounds, carbon atoms may form single, double or triple covalent bonds. Compounds in which the carbon atoms are linked to each other by single bonds are called saturated carbon compounds whereas compounds having at least one carbon-carbon double or triple bond are called unsaturated carbon compounds. Compounds containing only carbon and hydrogen are known as hydrocarbons. Based on the above information, answer the following questions. v. What is common name and molecular formula of ethyne?

Carbon forms a large number of compounds because of its two unique properties formed many have long straight chains of carbon, branched chains of carbon or rings of carbon. In these compounds, carbon atoms may form single, double or triple covalent bonds. Compounds in which the carbon atoms are linked to each other by single bonds are called saturated carbon compounds whereas compounds having at least one carbon-carbon double or triple bond are called unsaturated carbon compounds. Compounds containing only carbon and hydrogen are known as hydrocarbons. Based on the above information, answer the following questions. iv. Give IUPAC names of first two members of hydrocarbon which contain carbon-carbon double bonds.

Read the following paragraph and answer the following questions given below it : Construction of a compound microscope : (i) Acompound microscope consists of a metal tube fitted with two convex lenses at the two ends. These lenses are called the objective lens ( the lens directed towards the object ) and the eyepiece ( the lens directed towards the eye ). Both the lenses are small in size , but the cross section of the objective lens has a short focal length . the focal length of the eyepiece is more than that of the objective lens . (ii) The metal tube is mounted on a stand . thr principal axes of the objective lens and the eyepiece are along the same line . The distance between the object and objective lens can be changed with a screw . It is possible to change the distance between the objective lens and the eyepiece. Working : (i) The object to be observed is illuminated and placed in front of the objective lens. slightly beyond the focal length of the objective lens. it's real , inverted and enlarged image is formed by the objective lens on the other side. (ii) This intermediate image lies with in the focal length of the eyepiece. It serves as an object for the eyepiece. The eyepiece works as a simple microscope . the final image is virtual, highly enlarged and inverted with respect to the original object . It can be formed at the minimum distance of distinct vision from the eyepiece . The final image is observed by keeping the eye close to the eyepiece. Use: This microscope is used to observe blood cells , microorganisms , etc. In a compound microscope , which lens has greater focal length ?