*Question*
Q: What layered form of carbon is used as a lubricant and in pencils? Read this paragraph and choose the correct option from the provided answers: Graphite is a form of carbon in which carbon atoms are arranged in layers. Bonds are strong between carbon atoms within each layer but relatively weak between atoms in different layers. The weak bonds between layers allow the layers to slide over one another. This makes graphite relatively soft and slippery. It is used as a lubricant. It also makes up the "lead" in pencils. Choices: - carbonite - copper - lead - graphite A:
**Answer**
graphite

*Question*
Q: What type of generators use electromagnetic induction to change kinetic energy to electrical energy? Read this paragraph and choose the correct option from the provided answers: Two important devices depend on electromagnetic induction: electric generators and electric transformers. Both devices play critical roles in producing and regulating the electric current we depend on in our daily lives. Electric generators use electromagnetic induction to change kinetic energy to electrical energy. They produce electricity in power plants. Electric transformers use electromagnetic induction to change the voltage of electric current. Some transformers increase voltage and other decrease voltage. Choices: - conductors - radiators - thermal generators - electric generators A:
**Answer**
electric generators

*Question*
Q: What do we call the energy of motion? Read this paragraph and choose the correct option from the provided answers: The energy of motion is called kinetic energy. Choices: - electromagnetic energy - harmonic energy - binary energy - kinetic energy A:
**Answer**
kinetic energy

*Question*
Q: Many ceramics are composed of what, which are salts containing anions composed of silicon and oxygen? Read this paragraph and choose the correct option from the provided answers: At 1600 C, quartz melts to yield a viscous liquid. When the liquid cools, it does not crystallize readily but usually supercools and forms a glass, also called silica. The SiO4 tetrahedra in glassy silica have a random arrangement characteristic of supercooled liquids, and the glass has some very useful properties. Silica is highly transparent to both visible and ultraviolet light. For this reason, it is important in the manufacture of lamps that give radiation rich in ultraviolet light and in certain optical instruments that operate with ultraviolet light. The coefficient of expansion of silica glass is very low; therefore, rapid temperature changes do not cause it to fracture. CorningWare and other ceramic cookware contain amorphous silica. Silicates are salts containing anions composed of silicon and oxygen. In nearly all silicates, sp3-hybridized silicon atoms occur at the centers of tetrahedra with oxygen at the corners. There is a variation in the silicon-to-oxygen ratio that occurs because silicon-oxygen tetrahedra may exist as discrete, independent units or may share oxygen atoms at corners in a variety of ways. In addition, the presence of a variety of cations gives rise to the large number of silicate minerals. Many ceramics are composed of silicates. By including small amounts of other compounds, it is possible to modify the physical properties of the silicate materials to produce ceramics with useful characteristics. Choices: - vinylates - crystals - soils - silicates A:
**Answer**
silicates