Mastering Your Learning

Which is not a safety guideline?

• Eating is not allowed in the laboratory.

• Long hair should be tied up.

• The safety shower can be used to cool us down on a hot day.

• Wash hands before leaving the laboratory.

What does this hazard symbol represent?

• corrosive substance

• flammable substance

• irritant substance

• toxic substance

What does this hazard symbol represent?

• corrosive substance

• flammable substance

• irritant substance

• toxic substance

What does this hazard symbol represent?

• corrosive substance

• flammable substance

• irritant substance

• toxic substance

What does this hazard symbol represent?

• corrosive substance

• flammable substance

• irritant substance

• toxic substance

Which is a good practice when handling a corrosive liquid?

• Heat the liquid strongly.

• Hold the test tube containing the liquid carefully with your hands.

• Point the mouth of the test tube containing the liquid at a friend when heating the liquid.

• Wear gloves when handling the liquid

A student tried to light a Bunsen burner but was unsuccessful. What is a possible reason for this, given that both the Bunsen burner and the lighter were not faulty?

• The air-hole was closed.

• The gas was flowing out from the top of the Bunsen burner.

• The lighter was not placed directly above the Bunsen burner.

• The rubber tubing was connected to the Bunsen burner and gas tap.

Which situation requires only an estimate?

• choosing a suitable bag to store 20 potatoes

• constructing light bulbs to fit into a certain socket

• cutting a piece of glass to fit the door frame

• measuring the temperature of a child who has a high fever

Which row correctly shows the unit of measurement and its symbol for the measurement of mass?

• centimetre - cm

• centimetre - m

• gram - g

• gram - gr

The figure below shows the reading for a measurement of length. What is the likely error while taking the measurement?

• Neither end of the object was placed at the '0' mark.

• The eyes were not positioned in a straight line directly above the markings of the ruler.

• The eyes were slanted in the same direction.

• The reading was taken from only one position.