(Q).
Answer the following question given this paragraph: A binary molecular compound is a molecular compound that is composed of two elements. The elements that combine to form binary molecular compounds are both nonmetal atoms. This contrasts with ionic compounds, which were formed from a metal ion and a nonmetal ion. Therefore, binary molecular compounds are different because ionic charges cannot be used to name them or to write their formulas. Another difference is that two nonmetal atoms will frequently combine with one another in a variety of ratios. Consider the elements nitrogen and oxygen. They combine to make several compounds including NO, NO 2 , and N 2 O. They all can't be called nitrogen oxide. How would someone know which one you were talking about? Each of the three compounds has very different properties and reactivity. A system to distinguish between compounds such as these is necessary. Q: A binary molecular compound is made up of two of what? Choices: - compounds - cells - wafers - elements A:
(A).
elements

(Q).
Answer the following question given this paragraph: Coelacanths are ancient fish with just two living species. They are at risk of extinction because of their very small numbers. Q: Which ancient fish has just two living species and is at risk of extinction? Choices: - latimeria - hominids - squids - coelacanths A:
(A).
coelacanths

(Q).
Answer the following question given this paragraph: Measurement of exposure to radioactivity is important for anyone who deals with radioactive materials on a regular basis. Perhaps the simplest device is a personal dosimeter a film badge that will fog up when exposed to radiation. The amount of fogging is proportional to the amount of radiation present. These devices are not very sensitive to low levels of radiation. More sensitive systems use crystals that respond in some way to radioactivity by registering the number of emissions in a given time. These systems tend to be more sensitive and more reliable than film badges. Q: What is used by sensitive systems to detect even low levels of radiation? Choices: - electrons - radars - ions - crystals A:
(A).
crystals