Micro-organisms friend and foe — Science STD 8 — Question

State the causative micro-organisms and modes of transmission of the following human diseases:

1. Tuberculosis.
2. Measles.
3. Chickenpox.
4. Polio.
5. Cholera
6. Typhoid.
7. Hepatitis B.
8. Malaria.
9. Dengue.

What do you understand by the term migration?

What would you observe when a strip of zinc is placed in copper sulphate solution? Write a word equation of the reaction which takes place.

Two plane mirrors are set at right angles to each other. A coin is placed in-between these two plane mirrors. How many images of the coin will be seen?

Consider the following materials:
Copper, Sulphur, Phosphorus, Carbon (such as: pencil lead), Gold, Silver
Which of these materials are: Malleable and ductile; and brittle.

State the harmful effects of taking drugs.

What is the nature (acidic/ basic) of the following oxides?

1. Magnesium oxide
2. Sulphur dioxide

Given reason for your choice.

Why should we not let water collect anywhere in the neighbourhood?

How will you find out whether an object is charged or not?

Do all the stars in the sky move? Explain.