Atom, attract, charge, cloth, conductor, current, electrons, friction, insulation, negative, ammeter, plastic rod, positive, protons, repel, rubber, rubbing, spark, static Lightning is a dramatic natural force. But what causes it? On a smaller scale, a ………..can be produced in the lab. Sparks and lightning are both the flow of ………. In each case the charge is built up by ……….. Some objects can become charged simply by ………. them. The charge on this ……… ………..is too small to form a spark, but big enough to ………..pieces of paper, and big enough to influence the path of this stream of water. To find out why the rod becomes charged you have to think about what’s happening to the atoms it’s made up of.
Atoms contain positive charges called ………… and ………. charges called electrons. Normally the number of protons and electrons is the same so the ………has no overall charge. It’s neutral. Friction between the ……….. and rod changes this balance. In this case the cloth rubs …….. off the atoms in the rod so the rod becomes positively charged. A Van de Graaff generator produces enough charge to generate a spark. Take a look inside and you can see a motorized ……… belt. It passes around a Perspex roller at the bottom and at the top. As the belt rubs against the roller it acts like the cloth on the plastic rod. It rubs off electrons leaving the rod positive, while the belt becomes negative. The electrons are collected by a spring and transferred to the metal dome. Because it has nowhere else to go the charge builds up. It can’t move from the dome so it’s called static charge. Place a ………..near it, like this small metal sphere and the charge can move. It leaps across producing a spark. Charge builds up on anything in contact with the dome. Each fibre of Lindsey’s hair becomes negatively charged. Like charges ……….. so they move as far away as possible from each other. But for this to work the charge needs to be …………. It mustn’t leak away. Standing on polystyrene blocks acts as good ………...
What would happen if Lindsey stepped down onto the floor? Connecting a wire to the dome provides a path for the charge to flow along. It travels through an ………….. which is connected to the base of the generator to complete a circuit. The ammeter registers a flow of ………….. Electricity is simply a flow of negative charge. Static electricity becomes a flow of electricity as soon as it’s able to move. A fluorescent tube held next to the charged dome flickers as flows.

ruslanabbyasov2004    1   12.02.2021 12:10    1