Periodic Classification of Elements — Science STD 10 — Question

Explain why, graphite can be used as a lubricant but diamond cannot.

Explain vegetative propagation with the help of two examples. List two advantages of vegetative propagation.

A substance X is added to LPG cylinders while filling so as to make the detection of leakage of LPG from the cylinder easy.

1. Name the substance X.
2. How does substance X make the detection of leakage of LPG easy?

Hydrogen is not a metal but still it has been assigned a place in the reactivity series of metals. Why?

Explain the given reaction with the example:Hydrogenation reaction.

A convex mirror used as a rear-view mirror in a car has a radius of curvature of 3m. If a bus is located at a distance of 5m from this mirror, find the position of image. What is the nature of the image?

Calculate the number of electrons constituting one coulomb of charge.

Explain how, offspring and parents of organisms reproducing sexually have the same number of chromosomes?

Draw a ray diagram to show the formation of a real diminished image of an object by a convex lens. In your diagram, the position of object and image with respect to the principal focus should be shown clearly.

Explain the given reaction with the example:Hydrogenation reaction.