Answer the following question given this paragraph: A mineral is a solid material that forms by a natural process. A mineral can be made of an element or a compound. It has a specific chemical composition that is different from other minerals. One mineral's physical properties differ from others'. These properties include crystal structure, hardness, density and color. Each is made of different elements. Each has different physical properties. For example, silver is a soft, shiny metal. Salt is a white, cube-shaped crystal. Diamond is an extremely hard, translucent crystal. Q: A mineral can be made of an element or a? Choices: - Sediment - component - cell - compound A:
compound
(Question)
Answer the following question given this paragraph: Chapter 7 The Periodic Table and Periodic Trends In , we presented the contemporary quantum mechanical model of the atom. In using this model to describe the electronic structures of the elements in order of increasing atomic number, we saw that periodic similarities in electron configuration correlate with periodic similarities in properties, which is the basis for the structure of the periodic table. For example, the noble gases have what is often called filled or closed-shell valence electron configurations. These closed shells are actually filled s and psubshells with a total of eight electrons, which are called octets; helium is an exception, with a closed 1s shell that has only two electrons. Because of their filled valence shells, the noble gases are generally unreactive. In contrast, the alkali metals have a single valence electron outside a closed shell and readily lose this electron to elements that require electrons to achieve an octet, such as the halogens. Thus because of their periodic similarities in electron configuration, atoms in the same column of the periodic table tend to form compounds with the same oxidation states and stoichiometries. ended with the observation that, because all the elements in a column have the same valence electron configuration, the periodic table can be used to find the electron configuration of most of the elements at a glance. Q: What do halogens require electrons to achieve? Choices: - coupling - formation - fusion - octet A:
(Answer)
octet
Ques: Answer the following question given this paragraph: which is identical to the Rydberg equation for R = k . When Bohr calculated his theoretical value for the hc Rydberg constant, R , and compared it with the experimentally accepted value, he got excellent agreement. Since the Rydberg constant was one of the most precisely measured constants at that time, this level of agreement was astonishing and meant that Bohr's model was taken seriously, despite the many assumptions that Bohr needed to derive it. The lowest few energy levels are shown in Figure 6.14. One of the fundamental laws of physics is that matter is most stable with the lowest possible energy. Thus, the electron in a hydrogen atom usually moves in the n = 1 orbit, the orbit in which it has the lowest energy. When the electron is in this lowest energy orbit, the atom is said to be in its ground electronic state (or simply ground state). If the atom receives energy from an outside source, it is possible for the electron to move to an orbit with a higher n value and the atom is now in an excited electronic state (or simply an excited state) with a higher energy. When an electron transitions from an excited state (higher energy orbit) to a less excited state, or ground state, the difference in energy is emitted as a photon. Similarly, if a photon is absorbed by an atom, the energy of the photon moves an electron from a lower energy orbit up to a more excited one. We can relate the energy of electrons in atoms to what we learned previously about energy. The law of conservation of energy says that we can neither create nor destroy energy. Thus, if a certain amount of external energy is required to excite an electron from one energy level to another, that same amount of energy will be liberated when the electron returns to its initial state (Figure 6.15). In effect, an atom can "store" energy by using it to promote an electron to a state with a higher energy and release it when the electron returns to a lower state. The energy can be released as one quantum of energy, as the electron returns to its... Q: When an electron transitions from an excited state to a less excited state, or ground state, the difference in energy is emitted as a what? Choices: - neutron - nucleus - quark - photon A:
Ans: photon
(Q).
Answer the following question given this paragraph: Steroid Hormones The primary hormones derived from lipids are steroids. Steroid hormones are derived from the lipid cholesterol. For example, the reproductive hormones testosterone and the estrogenswhich are produced by the gonads (testes and ovaries)are steroid hormones. The adrenal glands produce the steroid hormone aldosterone, which is involved in osmoregulation, and cortisol, which plays a role in metabolism. Like cholesterol, steroid hormones are not soluble in water (they are hydrophobic). Because blood is water-based, lipidderived hormones must travel to their target cell bound to a transport protein. This more complex structure extends the half-life of steroid hormones much longer than that of hormones derived from amino acids. A hormone's half-life is the time required for half the concentration of the hormone to be degraded. For example, the lipid-derived hormone cortisol has a half-life of approximately 60 to 90 minutes. In contrast, the amino acidderived hormone epinephrine has a half-life of approximately one minute. Q: The primary hormones derived from lipids are what? Choices: - amino acids - melatonins - antibiotics - steroids A:
(A).
steroids
Ques:Answer the following question given this paragraph: The notochord lies between the dorsal nerve cord and the digestive tract. It provides stiffness to counterbalance the pull of muscles. Q: What rod provides stiffness to counterbalance the pull of muscles? Choices: - vertebrae - spinal cord - mesoderm - notochord A:

Ans:notochord
Ques: Answer the following question given this paragraph: Look at the battery and light bulb in Figure below . The light bulb works and it's connected to the battery, but it won't light. The problem is the loose wire on the left. It must be connected to the positive terminal of the battery in order for the bulb to light up. The reason? Electric current can flow through a material such as a wire only if the material forms a closed loop. Charges must have an unbroken path to follow between the positively and negatively charged parts of the voltage source, in this case, the battery. Q: Because charges must have an unbroken path to follow, electric current cannot flow through a material unless it forms what? Choices: - complete loop - closed area - total loop - closed loop A:
Ans:
closed loop