(Question)
Answer the following question given this paragraph: What do these two photos have in common? They both represent electromagnetic waves. These are waves that consist of vibrating electric and magnetic fields. They transmit energy through matter or across space. Some electromagnetic waves are generally harmless. The light we use to see is a good example. Other electromagnetic waves can be very harmful and care must be taken to avoid too much exposure to them. X rays are a familiar example. Why do electromagnetic waves vary in these ways? It depends on their properties. Like other waves, electromagnetic waves have properties of speed, wavelength, and frequency. Q: Vibrating electric and magnetic fields make up what kinds of waves? Choices: - seismic - eletrical - mechanical - electromagnetic A:
(Answer)
electromagnetic

(Question)
Answer the following question given this paragraph: The force that a magnet exerts is called magnetic force. The force is exerted over a distance and includes forces of attraction and repulsion. A magnet can exert force over a distance because the magnet is surrounded by a magnetic field. Q: What force includes forces of attraction and repulsion? Choices: - centripetal force - gravitational force - molecular force - magnetic force A:
(Answer)
magnetic force

(Question)
Answer the following question given this paragraph: The student athlete in Figure below is practically flying down the track! Running takes a lot of energy. But you don't have to run a race to use energy. All living things need energy all the time just to stay alive. The energy is produced in chemical reactions. A chemical reaction is a process in which some substances, called reactants, change chemically into different substances, called products. Reactants and products may be elements or compounds. Q: What is a process where some substances called reactants change chemically into different substances called products? Choices: - crystals reaction - carbon reaction - non-chemical reaction - chemical reaction A:
(Answer)
chemical reaction