Lecture 0 Flashcards by Nathalie Hayot

A substance that cannot be broken down into other substances by ordinary chemical procedures is a(n) _____________________.

a. element
b. compound
c. isotope
d. proton
e. molecule

a. element

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Which of the following statements is FALSE?

a. Iron is needed by all humans
b. Some naturally occurring elements are toxic to organisms
c. All life requires the same essential elements
d. Carbon, hydrogen, oxygen, and nitrogen are the most abundant elements of living matter

c. All life requires the same essential elements

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Which of the following best describes the relationship between the atoms described below?
Atom 1 = (1)(1)H
Atom 2 = (3)(1)H
a. They are isotopes
b. They contain 1 and 3 protons, respectively
c. They are isomers
d. They each contain only 1 neutron

a. They are isotopes

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Magnesium has an atomic number of 12. What is the most stable charge for a magnesium ion?

a. a +1 charge
b. a +2 charge
c. a -2 charge
d. a -1 charge

b. a +2 charge

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Which of the atoms below would be most likely to form a cation with a charge of +1?

a. Atom with 6 valence electrons
b. Atom with 9 valence electrons
c. Atom with 3 valence electrons
d. Atom with 8 valence electrons

c. Atom with 3 valence electrons

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Can the atomic mass of an element vary?

a. Yes. Adding or losing protons will change the atomic mass without forming a different element
b. Yes. Adding or losing neutrons will change the atomic mass without forming a different element
c. No, it is fixed. If it changes at all then you have formed a different element
d. Yes. Adding or losing electrons will substantially change the atomic mass

b. Yes. Adding or losing neutrons will change the atomic mass without forming a different element

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A carbon atom and a hydrogen atom form what type of bond in a molecule?

a. polar covalent bond
b. ionic bond
c. hydrogen bond
d. nonpolar covalent bond
e. Van der Waals interaction

d. nonpolar covalent bond

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An ionic bond is formed when ____________.

a. one atom transfers an electron to another atom
b. atoms are subjected to radioactive isotopes
c. both atoms are electrically neutral
d. both atoms are nonpolar
e. both atoms are equally attractive to electrons

a. one atom transfers an electron to another atom

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Nitrogen (N) is more electronegative than hydrogen (H). Which of the following is a correct statement about the atoms in ammonia (NH3)?

a. Ammonia has an overall positive charge.
b. The nitrogen atom has a partial positive charge; each hydrogen atom has a partial negative charge
c. Ammonia has an overall negative charge
d. Each hydrogen atom has a partial positive charge; the nitrogen atom has a partial negative charge

d. Each hydrogen atom has a partial positive charge; the nitrogen atom has a partial negative charge

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How many electrons are involved in a single covalent bond?

a. one
b. two
c. three
d. four

b. two

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The atomic number of sulfur is 16. Sulfur combines with hydrogen by covalent bonding to form a compound, hydrogen sulfide. Based on the number of valence electrons in a sulfur atom, predict the molecular formula of the compound.

a. H2S
b. HS
c. HS2
d. H3S2
e. H4S

a. H2S

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In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by ______.

a. ionic bonds
b. polar covalent bonds
c. nonpolar covalent bonds
d. hydrogen bonds

b. polar covalent bonds

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Sulfur is in the same column of the periodic table as oxygen, but has electronegativity similar to carbon. Compared to water molecules, molecules of H2S will ____________.

a. not form hydrogen bonds with each other
b. have a greater tendency to form hydrogen bonds with each other
c. have greater cohesion to other molecules of H2S
d. have a higher capacity to absorb heat for the same change in temperature

a. not form hydrogen bonds with each other

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Many of water’s emergent properties, such as its cohesion, its high specific heat, and its high heat of vaporization, result from the fact that water molecules _________________.

a. are extremely large
b. tend to repel each other
c. are very small
d. are in constant motion
e. are attracted to each other by partial negative and positive charges on the oxygen and hydrogen atoms, respectively

e. are attracted to each other by partial negative and positive charges on the oxygen and hydrogen atoms, respectively

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Which of the following is property of liquid water? Liquid water _________________.

a. is nonpolar
b. has a specific heat that is lower than that for most other substances
c. has a heat of vaporization that is higher than that for most other substances
d. is less dense than ice

c. has a heat of vaporization that is higher than that for most other substances

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Sodas typically contain sugar, flavorings, coloring agents, and carbon dioxide dissolved in water. The best term to describe this mixture would be ___________________.

a. a suspension
b. a solute
c. a solvent
d. an aqueous solution
e. an aqueous solvent

d. an aqueous solution

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Why does ice float in liquid water?

a. The ionic bonds between the molecules in ice prevent the ice from sinking
b. The high surface tension of liquid water keeps the ice on top
c. The crystalline lattice of ice causes it to be denser than liquid water
d. Stable hydrogen bonds keep water molecules of ice farther apart than water molecules of liquid water

d. Stable hydrogen bonds keep water molecules of ice farther apart than water molecules of liquid water

You have freshly prepared 0.1M glucose solution. Each liter of this solution contains how many glucose molecules?

a. 3.01 x 10^23
b. 6.02 x 10^22
c. 6.02 x 10^23
d. 6.02 x 10^24

b. 6.02 x 10^22

Select the statement that best describes a buffer.

a. A buffer stabilizes the pH of a solution by preventing acids or bases from dissociating
b. A buffer resists change in pH by accepting hydrogen ions when acids are added to the solution and donating hydrogen ions when bases are added
c. A buffer causes acidic solutions to become alkaline, and alkaline solutions to become acidic
d. A buffer prevents the pH of a solution from changing when an acid or base is added
e. Buffered solutions are always neutral, with a pH of 7

b. A buffer resists change in pH by accepting hydrogen ions when acids are added to the solution and donating hydrogen ions when bases are added

Which of the following dissociates completely in solution and is considered to be a strong base (alkali)?

a. NH3
b. NaOH
c. H2CO3
d. HCl

b. NaOH

Assume that acid rain has lowered the pH of a particular lake to pH 4.0. What is the hydroxide ion concentration of this lake?

a. 4.0M with regard to hydroxide ion concentration
b. 4.0 x 10^-4 mol of hydroxide ions per liter of lake water
c. 1 x10^-10 mol of hydroxide ions per liter of lake water
d. 1 x 10^-4 mol of hydroxide ions per liter of lake water

c. 1 x10^-10 mol of hydroxide ions per liter of lake water

Vitalism gave way to mechanism, the view that _________________.

a. physical and chemical laws govern living systems
b. bond angles are unpredictable
c. life on Earth began by way of abiotic synthesis of organic compounds
d. there was a life force outside the jurisdiction of physical and chemical laws
e. carbon’s ability to form four covalent bonds makes complex molecules possible

a. physical and chemical laws govern living systems

The complexity and variety of organic molecules is due to ____________.

a. the chemical versatility of carbon atoms
b. their interaction with water
c. the diverse bonding patterns of nitrogen
d. the variety of rare elements in organic molecules

a. the chemical versatility of carbon atoms

Which of the following is a hydrocarbon?

a. H2CO3
b. C6H12O6
c. C3H8
d. CCl2F2
e. CO2

c. C3H8

Which of the following best describes cis-trans isomers? a. They differ in the arrangement of covalent bonds and in covalent partners b. They have the same number of atoms of the same elements but different structures c. They are long chains of hydrogen and carbon atoms d. They differ in their spatial arrangement around inflexible double bonds e. They are mirror images of each other

d. They differ in their spatial arrangement around inflexible double bonds

A carbon atom is most likely to form what kind of bond(s) with other atoms? a. covalent b. ionic bonds, covalent bonds, and hydrogen bonds c. ionic d. hydrogen

a. covalent

Research indicates that ibuprofen, a drug used to relieve inflammation and pain, is a mixture of two enantiomers; that is, molecules that __________. a. differ in the location of their double bonds b. have identical chemical formulas but differ in the branching of their carbon skeletons c. are mirror images of each other d. differ in the arrangement of atoms around their double bonds

c. are mirror images of each other

Citric acid makes lemons taste sour. Which of the following is a functional group that would cause a molecule such as citric acid to be acidic? a. carboxyl b. amino c. carbonyl d. hydrocarbon e. hydroxyl

a. carboxyl | (carboxyl group can release a H ion when in solution)

Which of the following is a FALSE statement concerning amino groups? Amino groups ___________. a. contain nitrogen b. are found in amino acids c. are basic with respect to pH d. are nonpolar

d. are nonpolar

The smallest cell structure that would most likely be visible with a standard (not super-resolution) research-grade light microscope is a ________________. a. ribosome b. mitochondrion c. microtubule d. microfilament

b. mitochondrion

Which of the following clues would tell you if a cell is prokaryotic or eukaryotic? a. the presence or absence of a rigid cell wall b. whether or not the cell carries out cellular metabolism c. the presence or absence of ribosomes d. whether or not the cell contains DNA e. whether or not the cell is partitioned by internal membranes

e. whether or not the cell is partitioned by internal membranes

All of the following are part of a prokaryotic cell EXCEPT __________________. a. a cell wall b. an endoplasmic reticulum c. ribosomes d. a plasma membrane

b. an endoplasmic reticulum

Which structure is common to plant and animal cells? a. centriole b. chloroplast c. central vacuole d. mitochondrion

d. mitochondrion

Which organelle or structure is absent in plant cells? a. mitochondria b. centrosomes c. peroxisomes d. microtubules

b. centrosomes

Which statement correctly describes the nuclear envelope of a eukaryotic cell? a. The nuclear envelope is a single membrane, consisting of a phospholipid bilayer b. Plasmadesmosomes in the nuclear envelope permit the exchange of macromolecules between the nucleus and the cytoplasm c. All of the proteins of the cell are synthesized on ribosomes bound on the nuclear envelope d. The nuclear envelope is continuous with the endoplasmic reticulum e. The outer layer of the nuclear envelope is coated with laminin

d. The nuclear envelope is continuous with the endoplasmic reticulum

Which one of the following statements about the endomembrane system is correct? a. Most of the phospholipids of the endomembrane system are synthesized in the mitochondria b. The endoplasmic reticulum is continuous with the plasma membrane c. Mitochondria function in the modification and sorting of lipids and proteins d. Proteins that will be secreted from the cell are likely to be found in closed spaces bounded by membranes of the endomembrane system e. Ribosomes move lipids and proteins among the different organelles of the endomembrane system

d. Proteins that will be secreted from the cell are likely to be found in closed spaces bounded by membranes of the endomembrane system

The liver is involved in detoxification of many poisons and drugs. Which of the following structures is primarily involved in this process and, therefore, abundant in liver cells? a. smooth ER b. rough ER c. Golgi apparatus d. nuclear envelope

a. smooth ER

Suppose a cell has the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. It could be a cell from ___________. a. an animal but not a plant b. a plant but not an animal c. nearly any eukaryotic organism d. a bacterium

c. nearly any eukaryotic organism

A mutation that disrupts the ability of an animal cell to add polysaccharide modifications to proteins would most likely cause defects in its ________________. a. nuclear matrix and extracellular matrix b. Golgi apparatus and extracellular matrix c. mitochondria and Golgi apparatus d. nuclear pores and secretory vesicles

b. Golgi apparatus and extracellular matrix

In plant cells, the middle lamella ____________. a. maintains the plant's circulatory system b. allows adjacent cells to adhere to one another c. prevents dehydration of adjacent cells d. allows for gas and nutrient exchange among adjacent cells

b. allows adjacent cells to adhere to one another

The extracellular matrix is thought to participate in the regulation of animal cell behavior by communicating information from the outside to the inside of the cell via which of the following? a. gap junctions b. DNA and RNA c. the nucleus d. integrins

d. integrins