Exam 1 Figures

Exam 1 Figures - Figure 2.4 (p. 22): The lowest energy...

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- Figure 2.4 (p. 22): - The lowest energy level or electron shell—the one nearest the nucleus—is level K . It is occupied by a single s orbital, referred to as 1s. The next highest level, L, is occupied by 4 orbitals: one s orbital (referred to as the 2 s orbital) and three p orbitals (each referred to as a 2p orbital). The four L-level orbitals compactly fill the space around the nucleus, like 2 pyramids set base-to-base. Thus, the lowest energy level, K, is populated by 2 electrons, while the next highest energy level, L, is populated by a total of 8 electrons. - Figure 2.5 (p. 23) - When an electron absorbs energy, it moves to higher energy levels, farther from the nucleus. When an electron releases energy, it falls to lower energy levels, closer to the nucleus. - Figure 2.8 (p. 25) - When a sodium atom donates to a chlorine atom, the sodium atom becomes a positively charged sodium ion, and the chlorine atom becomes a negatively charged chloride ion. Sodium chloride (NaCl) forms a highly regular lattice of alternating sodium ions and chloride ions. - Figure 2.10a (26) - Hydrogen gas is a diatomic molecule, meaning that it is composed of two hydrogen atoms, each sharing its electron with the other. - Figure 2.11 (p. 28) - The polar end of this organic molecule is interacting with a water molecule. This interaction bridges a hydrogen atom and is called a hydrogen bond. - Table 2.1 (p. 28) - Cohesion - Hydrogen bonds hold water molecules together - Leaves pull water upward from the roots; seeds swell and germinate - High specific heat - Hydrogen bonds absorb heat when they break, and release heat when they form, minimizing temperature changes - Water stabilizes the temperature of organisms and the environment - High heat of vaporization - Many hydrogen bonds must be broken for water to evaporate - Evaporation of water cools body surfaces - Lower density of ice - Water molecule in an ice crystal are spaced relatively far apart because of hydrogen bonding - Because ice is less dense than water, lakes do not freeze solid - Solubility - Polar water molecules are attracted to ions and polar compounds, making them soluble - Many kinds of molecules can move freely in cells, permitting a diverse array of chemical reactions - Figure 2.10 (p. 27) - Each water molecule is composed of one oxygen atom and two hydrogen atoms. The oxygen atom shares one electron with each hydrogen atom. - The greater electronegativity of the oxygen atom makes the water molecule polar: water carries two partial negative charges near the oxygen atom and two partial positive charges, one on each hydrogen atom. - Figures 3.23 (p. 55) - Monosaccharides, or simple sugars, can contain as few as 3 carbon atoms and are often used as building blocks to form larger molecules. Glyceraldehyde. -
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Exam 1 Figures - Figure 2.4 (p. 22): The lowest energy...

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