Q: Answer the following question given this paragraph: Gilbert Lewis (1875-1946) proposed a third theory of acids and bases that is even more general than either the Arrhenius or Brnsted-Lowry theories. A Lewis acid is a substance that accepts a pair of electrons to form a covalent bond. A Lewis base is a substance that donates a pair of electrons to form a covalent bond. So, a Lewis acid-base reaction is represented by the transfer of a pair of electrons from a base to an acid. A hydrogen ion, which lacks any electrons, accepts a pair of electrons. It is an acid under both the Brnsted-Lowry and Lewis definitions. Ammonia consists of a nitrogen atom as the central atom with a lone pair of electrons. The reaction between ammonia and the hydrogen ion can be depicted as shown in the Figure below . Q: A lewis acid is a substance that accepts a pair of electrons to form what? Choices: - accretion bond - functionality bond - ambivalent bond - covalent bond A:
A: covalent bond

Q: Answer the following question given this paragraph: The ears are also responsible for the sense of balance. Balance is the ability to sense and maintain body position. The semicircular canals inside the ear (see Figure above ) contain fluid that moves when the head changes position. Tiny hairs lining the semicircular canals sense movement of the fluid. In response, they send nerve impulses to the vestibular nerve , which carries the impulses to the brain. The brain interprets the impulses and sends messages to the peripheral nervous system. This system maintains the body's balance by triggering contractions of skeletal muscles as needed. Q: What is responsible for our sense of balance? Choices: - our eyes - our limbs - our feet - our ears A:
A: our ears

Q: Answer the following question given this paragraph: Global air currents cause global winds. The figure below shows the direction that these winds blow ( Figure below ). Global winds are the prevailing, or usual, winds at a given latitude. The winds move air masses, which causes weather. Q: Winds moving air masses causes what? Choices: - earthquake - tremors - tsunami - weather A:
A: weather

Q: Answer the following question given this paragraph: There is an associated magnetic field ( B ) which propagates outward as well (see Figure 24.6). The electric and magnetic fields are closely related and propagate as an electromagnetic wave. This is what happens in broadcast antennae such as those in radio and TV stations. Closer examination of the one complete cycle shown in Figure 24.5 reveals the periodic nature of the generator-driven charges oscillating up and down in the antenna and the electric field produced. At time t = 0 , there is the maximum separation of charge, with negative charges at the top and positive charges at the bottom, producing the maximum magnitude of the electric field (or E -field) in the upward direction. One-fourth of a cycle later, there is no charge separation and the field next to the antenna is zero, while the maximum. Q: The electric and magnetic fields are closely related and propagate as what? Choices: - mechanical wave - thermal energy - sound wave - electromagnetic wave A:
A: electromagnetic wave