Answer the following question given this paragraph:   Note the Pattern Few binary molecular compounds of nitrogen are formed by the direct reaction of the elements. At elevated temperatures, nitrogen reacts with highly electropositive metals to formionic nitrides, such as Li3N and Ca3N2. These compounds consist of ionic lattices formed by M n+ and N3− ions. Just as boron forms interstitial borides and carbon forms interstitial carbides, with less electropositive metals nitrogen forms a range ofinterstitial nitrides, in which nitrogen occupies holes in a close-packed metallic structure. Like the interstitial carbides and borides, these substances are typically very hard, high-melting materials that have metallic luster and conductivity. Nitrogen also reacts with semimetals at very high temperatures to produce covalent nitrides, such as Si3N4 and BN, which are solids with extended covalent network structures similar to those of graphite or diamond. Consequently, they are usually high melting and chemically inert materials. Ammonia (NH3) is one of the few thermodynamically stable binary compounds of nitrogen with a nonmetal. It is not flammable in air, but it burns in an O2 atmosphere: Equation 22.30.   Q: What (nh3) is one of the few thermodynamically stable binary compounds of nitrogen with a nonmetal?   A:

OPTIONS:
- liquid nitrogen
- acetic acid
- nitrous oxide
- ammonia

Answer: ammonia


Answer the following question given this paragraph:   Contour lines are lines of equal elevation. Contour intervals are the difference in elevation between two contour lines.   Q: What is the term for the difference in elevation between two contour lines?   A:

OPTIONS:
- height
- design interval
- mapping interval
- contour interval

Answer: contour interval


Answer the following question given this paragraph:   Image copyright SergiyN, 2014. Coil of copper wire, which conducts electricity well due to metallic bonds . Used under license from Shutterstock. com.   Q: What gives a coil of copper wire the ability to conduct electricity well?   A:

OPTIONS:
- optical bonds
- metallic electrons
- metallic ions
- metallic bonds

Answer: metallic bonds


Answer the following question given this paragraph:      Q: What is occasional chest pain known as?   A:

OPTIONS:
- cardiac arrest
- arrhythmia
- heart murmur
- angina pectoris

Answer:
angina pectoris