(Q).
Q: In vertebrates, what structure runs from the brain to the tail end of the backbone? Read this paragraph and choose the correct option from the provided answers: Vertebrates have a centralized nervous system. As shown in Figure below , the nervous system consists of a brain in the head region. It also includes a long spinal cord that runs from the brain to the tail end of the backbone. Long nerve fibers extend from the spinal cord to muscles and organs throughout the body. Choices: - ribcage - aortic valve - backbone - spinal cord A:
(A).
spinal cord

(Q).
Q: Conversely, very large forces are created by liquids and solids when they try to expand but are constrained from doing sowhich is equivalent to compressing them to less than their normal volume. this often occurs when a contained material warms up, since most materials expand when they do this? Read this paragraph and choose the correct option from the provided answers: Conversely, very large forces are created by liquids and solids when they try to expand but are constrained from doing sowhich is equivalent to compressing them to less than their normal volume. This often occurs when a contained material warms up, since most materials expand when their temperature increases. If the materials are tightly constrained, they deform or break their container. Another very common example occurs when water freezes. Water, unlike most materials, expands when it freezes, and it can easily fracture a boulder, rupture a biological cell, or crack an engine block that gets in its way. Other types of deformations, such as torsion or twisting, behave analogously to the tension, shear, and bulk deformations considered here. Choices: - increase density - increase mass - decrease temperature - increase temperature A:
(A).
increase temperature

(Q).
Q: Which rule is a result of trends in energies and is useful in explaining why atoms form the ions that they do? Read this paragraph and choose the correct option from the provided answers: valence shell is called the octet rule. When atoms form compounds, the octet rule is not always satisfied for all atoms at all times, but it is a very good rule of thumb for understanding the kinds of bonding arrangements that atoms can make. It is not impossible to violate the octet rule. Consider sodium: in its elemental form, it has one valence electron and is stable. It is rather reactive, however, and does not require a lot of energy to remove that electron to make the Na+ ion. We could remove another electron by adding even more energy to the ion, to make the Na2+ ion. However, that requires much more energy than is normally available in chemical reactions, so sodium stops at a 1+ charge after losing a single electron. It turns out that the Na+ ion has a complete octet in its new valence shell, the n = 2 shell, which satisfies the octet rule. The octet rule is a result of trends in energies and is useful in explaining why atoms form the ions that they do. Now consider an Na atom in the presence of a Cl atom. The two atoms have these Lewis electron dot diagrams and electron configurations:. Choices: - electrons rule - nutron rule - coupling rule - octet rule A:
(A).
octet rule