practice test ch 2 Flashcards
Foods are broken down into their building blocks by adding water. This would be an example of which characteristic of water?
Water acts as a reactant.
Water acts to dissolve molecules in the body. How does water dissolve the salt (NaCl) in your mouth from a salty pretzel?
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.
In plasma, a typical body fluid, protein floating around would be considered to be which of the following?
a solute, specifically both a colloid and an electrolyte
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?
chloride
Which pH is more acidic, a pH of 3, a pH of 7, or a pH of 9?
pH of 3
Cortisol is a type of lipid hormone. Which type of lipid would cortisol be classified as?
steroid
Formation of hydrogen bonds requires hydrogen atoms and what else?
polar covalent bonds
Which of the following correctly ranks the types of chemical bonds, in order, from strongest to weakest?
covalent, ionic, hydrogen
Which of the following distinguishes hydrogen bonds from covalent bonds?
Only hydrogen bonds can form between molecules.
Which of the following is not a result of hydrogen bonds?
Two hydrogen atoms join together to form a molecule of hydrogen gas.
In a covalent bond,
Atoms share one or more pairs of electrons.
Covalent bonds:
involve the sharing of one to three pairs of electrons.
Which of the following is true of polar covalent bonds?
The electrons are shared unequally.
A molecule of water (H2O) is formed by what type of bond?
polar covalent bonds
Which parts of atoms can interact (react) to form chemical bonds?
valence electrons
Atoms of oxygen have a total of 8 electrons. Are these atoms stable, and why or why not?
No, because the atoms have only 6 valence electrons, but need 8 for stability.
Carbon atoms have four valence electrons. Are they likely to react with other atoms, and why or why not?
Yes, because they can become more stable by doing so.
Which of the following is not produced through chemical bonding?
atoms
Which type(s) of subatomic particles can be located within the nucleus of an atom?
protons and neutrons
Which subatomic particles contribute to an atom’s mass number but not its atomic number?
neutrons
An atom of oxygen has an atomic number of 8 and a mass number of 18. How many of each type of subatomic particle does it contain?
8 protons, 8 electrons, and 10 neutrons
Blood loss due to a moderate hemorrhage has several adverse effects on patient wellbeing. Why would administering IV fluids alone not be sufficient to return a patient to health?
Why can dehydration be such a life-threating event?
What is an ion?
an atom that has either gained or lost electron(s)
When an ionic bond forms, which part(s) of the atoms are directly involved?
the outermost electrons
