Practical work: making a night light
A night light is made in two ways: from polymer materials and from kapron (nylon). In the first, flower petals are cut from thin foamiran sheet by a paper template, coloured with dry pastel or pencil powder, threaded onto thin wire and wrapped with green tape; the bud is shaped from plastic clay made of cornstarch, PVA glue, glycerin and petroleum jelly (this clay is cooked by heating, so an adult makes it, or ready-made polymer clay is used). The light source is an LED: its longer leg is “+”, the shorter “−”, and a resistor that limits current is connected in front of the LED, otherwise it burns out. In the second method, petals and leaves are made of wire and kapron and wound around a ready-made LED garland. Safety: soldering the LED, joining wires and working with plugs is done only by the teacher or a qualified master, with the power off; for a pupil, using a ready-made battery-powered or low-voltage (USB) LED garland is the safest way; never connect an LED directly to the household socket. The glue gun and soldering iron get hot, scissors and knives are used under the teacher’s supervision, small parts (stones, beads) are not put in the mouth, and the workplace is ventilated.
Draw a schematic: battery, resistor and LED in series, marking the LED legs “+” and “−”. Making a light from foamiran flowers with a ready-made battery LED garland is done with the teacher; there is no soldering or mains connection in this activity.