Chapter 2 HW (A&P)

25 July 2022
4.7 (114 reviews)
18 test answers

Unlock all answers in this set

Unlock answers (14)
question
Which parts of atoms can interact (react) to form chemical bonds?
answer
valence electrons; Only the outermost parts of atoms interact (react) with each other, and those are the valence electrons. If the outermost orbital is full, the atom is stable and less likely to react with another atom.
question
Atoms of oxygen have a total of 8 electrons. Are these atoms stable, and why or why not?
answer
No, because the atoms have only 6 valence electrons, but need 8 for stability.; To be stable, by the Octet Rule an atom must have 8 electrons in its outermost orbital. With only 6 valence electrons, oxygen atoms are unstable and will seek ways to get or share two more electrons to become stable.
question
Foods are broken down into their building blocks by adding water. This would be an example of which characteristic of water?
answer
Water acts as a reactant; Yes, water molecules are necessary for salivary amylase to hydrolyze starch to glucose in your mouth. Thus, water acts as an important reactant.
question
Water acts to dissolve molecules in the body. How does water dissolve the salt (NaCl) in your mouth from a salty pretzel?
answer
Water acts as a solvent because the partial negative charge on the oxygen in water attracts sodium, while the partial positive charge on hydrogen attracts chloride. This results in the separation of sodium from chloride, thus breaking the ionic bond.; Yes, salt (NaCl) is an ionic compound that can be separated by the polar water molecule.
question
In plasma, a typical body fluid, protein floating around would be considered to be which of the following?
answer
a solute, specifically both a colloid and an electrolyte; Yes, colloids are large particles dispersed in body fluids. Since most proteins have a negative charge, they are also considered to be electrolytes.
question
Electrolytes are charged particles called ions that are dissolved in body fluids. Which of the following ions would be considered a major anion in the body?
answer
Chloride. Yes, chloride is a major extracellular anion (negative ion).
question
Which pH is more acidic, a pH of 3, a pH of 7, or a pH of 9?
answer
pH of 3; Yes, the lower the pH, the more acidic the fluid. pH is inversely related to the number of H+ ions. As the number of H+ ions increases (and thus the acidity increases), the pH decreases. Therefore, a pH of 3 is the most acidic of the three values given.
question
Cortisol is a type of lipid hormone. Which type of lipid would cortisol be classified as?
answer
steroid; Yes, cortisol is a steroid hormone synthesized from cholesterol.
question
Formation of hydrogen bonds requires hydrogen atoms and what else?
answer
polar covalent bonds; Hydrogen gets a slight positive charge from the unequal sharing of electrons in polar covalent bonds, and it bonds to another atom with a slightly negative charge, again resulting from unequal electron sharing due to a polar covalent bond.
question
Which of the following correctly ranks the types of chemical bonds, in order, from strongest to weakest?
answer
covalent, ionic, hydrogen; In covalent bonds, electrons are shared between atoms; in ionic bonds electrons are lost or gained; but hydrogen bonds are not true chemical bonds—they are weak attractions due to slight electrical imbalances. No electrons are directly involved.
question
Which of the following distinguishes hydrogen bonds from covalent bonds?
answer
only hydrogen bond can form between molecules; Because hydrogen bonds are not true bonds, they do not always join atoms together within a single molecule. In water, for example, hydrogen bonds link water molecules together. This is referred to as an intermolecular attraction—it is between different atoms.
question
Which of the following is not a result of hydrogen bonds?
answer
two hydrogen atoms come together to form a molecule hydrogen gas; Hydrogen bonds occur when there are polar covalent molecules present, but hydrogen atoms join with each other through nonpolar covalent bonds.
question
In a solution, the solute is the substance present in the greatest amount.
answer
False; In a solution, the solute is the substance present in lesser amounts. There may be many solutes.
question
All salts are ionic compounds, but not all ionic compounds are salts.
answer
True; Salts are ionic compounds that contain a cation other than H+ and an anion other than OH-.
question
The pH scale __________.
answer
is based on concentration of hydrogen ions in a solution; The pH scale, which ranges from 0 to 14, is a logarithmic scale based on the concentration of hydrogen ions in a solution.
question
What is the classification of a solution of NaOH with a pH of 8.3?
answer
alkaline solution; A pH between 0.0 and 7.0 is acidic. A pH between 7.0 and 14.0 is basic. Therefore, a solution with a pH of 8.3 is an alkaline (or basic) solution. NaOH is an example of a basic compound.
question
Which of the following is not produced through chemical bonding?
answer
atoms Atoms react through chemical bonding to form larger structures. Chemical bonding begins with atoms; it does not produce them. All of the structures that we cover in A&P are made from atoms through chemical bonding.
question
Carbon atoms have four valence electrons. Are they likely to react with other atoms, and why or why not?
answer
Yes, they can become more stable in doing so; Atoms react with other atoms to gain stability, typically by gaining, losing, or sharing electrons to attain a full outermost orbital. Atoms with full outermost electron orbitals are less likely to react and are referred to as being inert.