Acids, Bases and Salts — Science STD 10 — Question

When you smell a favourite food your mouth begins to water (that is, you secrete saliva). Write down what the following are examples of:
The smell of the food.

Which has less electrical resistance : a thin wire or a thick wire (of the same length and same material)?

Where does fertilisation take place in human females?

For what position of an object, a concave mirror forms a real image equal in size to the object?

Name an animal which depends on simple diffusion of gases for breathing.

What colour do the following indicators turn when added to a base or alkali (such as sodium hydroxide)?

1. Methyl orange.
2. Litmus.
3. Red cabbage extract.

In figure (a), (b) and (c), which appears more accurate and why?

Name one metal which has a low melting point.

Which property of copper metal is utilised in making thin wires?

Name one liquid carbon compound which is being used as an additive in petrol in some countries.