Material:

• A piece of newspaper or letters A, E, F and O written in square pieces of paper with 1cm²
• Scissors;
• Microscopic slide;
• Cover slip;
• Microscope;
• Water;
• Dropper;
• Filter paper;
• Ruler.

Procedures:

Cut the word "forma" from the newspaper (1cm²) or write it in square pieces of paper (1cm²);

Put one drop of water over the slide;

Put the word "forma" on the slide and drop one drop of water over the paper (figures 1a and 1b);

Remove the excess of water with the filter paper (figures 1c and 1d);

Elevate the body tube and the objective lens with the macrometric knob (figure 1e);

Place the slide (preparation) in the chariot or clips (figure 1f);

Light the microscopic field with the slide or mirror deviation (figure 1g);

Looking from the outside, turn the revolver until you have the objective lens with the least magnification;

Still looking from the outside, in order not to break the slide, turn the macrometric knob until the objective lens is near the slide;

Looking through the ocular lens, slowly turn the macrometric knob for the objective lens to go away from the slide until you have an image (figure 1h);

Turn the micrometric knob to focus the image;

To move to a higher magnification degree, repeat the operation with a greater magnification objective lens.

Figure 1: Assembly steps and visualisation of the specimen in the microscope

Occurrence:

The greater magnification objective lens allows visualisation of a smaller area;

The lower magnification objective lens allows visualisation of a larger area.

From the word selected only the larger syllabus was seen;

Letter "f" was seen inverted and repelled;

Letter "r" was seen inverted and repelled;

Letter "O" apparently was not seen inverted or repelled.

Procedures with the word "FEIRA":

The same procedures conducted for the word "forma" (figure 2);

Figure 2: Assembly steps and visualisation of the specimen in the microscope, and the result of the observation of the preparation under different magnification grades.

Conclusions:

The use of the greater magnification objective lens, as it allows visualisation of a smaller area, allows observation of details in the preparation in question.

The use of the lower magnification objective lens, as it allows visualisation of a larger area, allows observation of few details in the preparation in question;

Changes in the position of the letters were noted.