Carbon and its Compounds — Science STD 10 — Question

Which of the following elements would yield:

1. An acidic oxide.
2. A basic oxide.
3. A neutral oxide.

Na, S, C, K, H

Why does silicon has valency 4 and chlorine 1?

With the help of a diagram, show how when light falls obliquely on the side of a rectangular glass slab the emergent ray is parallel to the incident ray.

What is blood pressure? What are the two factors used to express the blood pressure of a person?

When the leaves of a sensitive plant are touched with a finger, they fold up and when light fades at dusk, the petals of a dandelion flower close.

1. State one way in which the above two processes are similar.
2. State two ways in which the above two processes differ.

Name any four types of ornamental plants which are being produced by tissue culture technique.

A gas is liberated immediately with a brisk effervescence, when you add acetic acid to sodium hydrogen carbonate powder in a test tube. Name the gas and describe the test that confirms the identity of the gas.

List three problems which arise due to construction of big dams. Suggest a solution for these problems.

Define "Parasite" Name two saprophytes and two parasites.