... releases heat. Examples of exothermic reactions: * Adding concentrated acid to water. * Nuclear fission. * Condensation of rain from water vapour. The word endothermic describes a process or reaction that absorbs energy in the form of heat. Examples of endothermic reactions: * Evaporation of water. * Melting solid salts. * Mixing water and ammonium nitrate. 4) Find 2 uses for a thermistor and 2 uses for a LDR. How does the change in their resistance make them suitable for these jobs? Thermistors can be used as replacements for fuses and as heating elements in small temperature controlled ovens. LDRs are used in street lights and clock radios. Change in resistance makes them suitable for their jobs because they change as the resistance changes- they depend on temperature and light. 5) Find the mains frequency and voltage of electricity in the USA, England and France. What does this mean about the safety of them and how possible it is to use an ...

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