BIOL 1201 EXAM 1
hydrogen; oxygen; hydrogen
A ____ atom with a net positive charge is attracted to an ____ atom with a net negative charge.thus forming a ____ bond.
covalent
A ____ is one in which electron pairs are shared.
ketones
A carbonyl group in the middle of a carbon skeleton characterizes ___.
6 electrons
A cation with two units of charge has 10 neutrons and 8 protons. The ion also has ...
covalently
A methyl group consists of a carbon ___ bonded to three hydrogen atoms.
electron-sharing.
A phrase that applies to covalent bonding and not other kinds of bonds is ...
10 degrees C
A slice of pizza has 500 kcal. If we could burn the pizza and use all the heat to warm a 50-L container of cold water, what would be the approximate increase in the temperature of the water? (Note: A liter of cold water weighs about 1 kg.)
sizes
A structural model is designed to show which atoms are bound to one another, but it doesn't accurately picture the ___ of atoms.
False
A theory in science is equivalent in scope to a well-structured hypothesis.
hydronium
A water molecule that gains a hydrogen becomes a ___ ion
amino
A(n) ___ group acts as a base and can pick up protons from the surrounding medium, becoming positively charged.
double covalent
A(n) _____ bond joins these two oxygen atoms because the oxygen atom is sharing two pairs of electrons.
molecule
A(n) _____ refers to two or more atoms held together by covalent bonds.
carbon, hydrogen, nitrogen, oxygen
About 25 of the 92 natural elements are known to be essential to life. Which four of these 25 elements make up approximately 96% of living matter?
1 in 500,000,000
About _____ molecules in a glass of water are dissociated.
electron orbital
An ___ describes a three-dimensional space where an electron can be found 90% of the time.
C; it has 6 protons
An atom has 6 electrons, 6 protons, and 6 neutrons. You can tell that this atom belongs to the element _____ because _____________________.
10 neutrons
An atom has 8 protons, 8 neutrons, and 8 electrons. Another isotope of the same element might have ...
3
An atom's atomic number is 7. Its valence is most likely ...
1
An electrically neutral molecule has the formula C3H4O2N. If the carbon atoms form the usual number of bonds, how many covalent bonds will each hydrogen atom have with other atoms in the molecule?
an attraction between ions of opposite charge
An ionic bond involves _____.
E
An orbital is dumbbell-shaped. Which statement is most likely true? A. Its electrons move along a figure-8 path. B. Each lobe can hold one electron. C. It's in the first electron shell. D. Each lobe can hold two electrons. E. None of the above.
tissues
An organ, such as the liver, is composed of ____.
5
An uncharged atom of boron has an atomic number of 5 and an atomic mass of 11. How many protons does boron have?
are different ions
Atoms with the same number of protons but with different electrical charges _____.
positively charged
Based on your knowledge of the polarity of water molecules, the solute molecule is most likely...
carboxyl
By donating hydrogen ions, ___ groups act as an acid.
Shared electrons aren't always near oxygen.
By making two covalent bonds, an O atom (with 8 protons) fills its valence shell. Why does the atom's charge stay close to zero?
no cells were entering the flask from the air; arisen spontaneously
By using a swan-necked flask for the experimental treatment, Pasteur ensured that ____. Thus, any organisms that appeared in the experimental flask would have ____.
20 protons.
Calcium has an atomic number of 20 and an atomic mass of 40. Therefore, a calcium atom must have
the graph steadily decreases
Carbon dioxide (CO2) is readily soluble in water, according to the equation CO2 +H2O→H2CO3. Carbonic acid (H2CO3) is a weak acid. If CO2 is bubbled into a beaker containing pure, freshly-distilled water, which of the following graphs correctly describes the results?
rely much less on electron-sharing.
Compared to covalent bonds, ionic bonds ...
some other factor
Controlling all variables but one ensures that ___ is not responsible for the results obtained from an experiment.
isotopes
Different atomic forms of an element contain the same number of protons but a different number of neutrons. What are these different atomic forms called?
both bonds are nonpolar
Dr. Haxton says the O-O bond is polar and the C-C bond is nonpolar. A good student would say ...
the first shell shouldn't have three electrons
Dr. Jones says an atom has 3 electrons in the first shell and four electrons in the second shell. Someone should tell Dr. Jones that ...
equally shared electrons
Each carbon-hydrogen bond involves a single pair of ___.
atomic number
Each element is unique and different from other elements because of the number of protons in the nuclei of its atoms. What indicates the number of protons in an atom's nucleus?
repels; equally
Each pair of electrons ___ the other pairs, so they are ___ far apart.
four; hydrogen
Each water molecule can be joined to a maximum of _____ other water molecules by ____ bonds.
are mirror images
Enantiomers are molecules that _____.
10
Fluorine's atomic number is 9 and its atomic mass is 19. How many neutrons does fluorine have?
sunlight; heat
For most ecosystems __________ is (are) the ultimate source of energy, and energy leaves the ecosystem in the form of __________.
15 protons and 15 electrons.
From its atomic number of 15, it is possible to predict that the uncharged phosphorus atom has
4
How many electron pairs does carbon share in order to complete its valence shell?
2
How many electrons would be expected in the outermost electron shell of an atom with atomic number 12?
60
How many grams of the substance in the figure would be equal to 1 mol of the substance? (Carbon = 12, Oxygen = 16, Hydrogen = 1)
C,D,E
Identify all correct statements about the ionization of water. A. Dissociation of water is not reversible. B. Water ionizes to form peroxide and hydronium ions. C. Dissociation of water is reversible. D. Water ionizes to form hydroxide and hydronium ions. E. Dissociation of water produces equal numbers of OH- and H+. F. Dissociation of water produces equal masses of OH- and H+.
H-N
If you want a molecule that is highly polar, look for one that contains:
polar covalent
In H2O: While oxygen shares electrons with hydrogen, the electrons spend more time with the oxygen than with the hydrogens, thus creating a ___ bond.
boiled the broth
In Pasteur's experiment to test the hypothesis of spontaneous generation, he ____ to kill any existing organisms in the broth and to ensure the conditions in each flask were identical.
neutral solution
In a ___ the concentration of hydrogen ions is equal to the concentration of hydroxide ions
electrons in two orbitals.
In a double covalent bond, a carbon atom shares ...
to eliminate alternative explanations
In an experiment, investigators try to control all of the variables except one—the one that tests the hypothesis. Which of the following reasons is the primary rationale for controlling variables in an experiment?
4,1,2,3
In molecules, C, H, O, and N atoms usually make __, __, __, and __ bonds respectively.
ionic
In salt, what is the nature of the bond between sodium and chlorine?
oxygen; hydrogen; zero
In the bonds of a water molecule, ___ holds electrons more tightly than ___ does, and the net charge is ___.
protons; neutrons
Isotopes have the same number of ___; different numbers of ___.
Parkinson's disease
L-dopa is used to treat _____.
higher
Molecules move more freely in liquid water than ice, and thus its entropy is ___.
weak; strong
NH3 is a ___ base (alkali), and HCl is a ___ acid.
polarity
O and H are at opposite ends of the electronegativity scale, so the ___ is very large.
two more neutrons than carbon-12.
One difference between carbon-12 (12:16 C) and carbon-14 (14:6 C) is that carbon-14 has
10,000 times more
One liter of a solution of pH 2 has how many more hydrogen ions (H+) than 1 L of a solution of pH 6?
100,000 times more
One liter of a solution pH 9 has how many more hydroxyl ions (OH-) than 1 L of a solution of pH 4?
second or higher shells
Only ___ have dumbbell-shaped orbitals.
covalent bonds
Only in ___ do atoms share electrons.
two
Organs are composed of ___ or more different tissues.
approximately 16 daltons.
Oxygen has an atomic number of 8 and a mass number of 16. Thus, the atomic mass of an oxygen atom is
electronegative
Oxygen is more ___ than hydrogen.
atoms share electrons unequally.
Partial charges occur when ...
dopamine
People with Parkinson's disease lack ___.
D
Polar attractions are ... (a) forces between atoms with partial charges. (b) weaker than covalent bonds. (c) important because they are numerous. (d) all of the above
nucleus; organelles
Prokaryotic cells lack the ___ and other ___ found in eukaryotic cells.
an atom has too many neutrons.
Radioactive decay is likely to occur when ...
single bonds
Rotation can occur around ___.
arrangement of carbon, hydrogen, and oxygen atoms.
Shown here in the figure are the structures of glucose and fructose. These two molecules differ in the...
positively; negatively
Sodium loses an electron and thus becomes ___ charged; chlorine gains an electron and thus becomes ___ charged.
family; order
Species that are in the same __________ are more closely related than species that are only in the same __________.
results would be invalid
Suppose that Zonosemata flies whose own wings had been clipped and reattached were attacked more frequently than untreated Zonosemata flies. How would this result affect the reliability of the other experimental results?
double bond
The ____ limits all the atoms to a plane.
ration of protons to neutrons
The atomic nucleus becomes unstable if the ______ is too far from unity.
8
The atomic number of carbon is 6. Carbon-14 is heavier than carbon-12 because the atomic nucleus of carbon-14 contains _____ neutrons.
14^silicon
The atomic number of each atom is given to the left of each of the elements below. Which of the atoms has the same valence as carbon 12:6 C?
It has 8 electrons in its outer electron shell and it is inert.
The atomic number of neon is 10. Therefore, which of the following is correct about an atom of neon?
atoms tend to have filled valence shells.
The atoms shown here will become ions if they meet because ...
stomach and small intestine
The digestive system is composed of structures such as the....
hydrogen
The electronegativity of nitrogen means that amino groups tend to pick up___ ions.
common ancestry
The fact that all organisms share a single genetic code is due to their ___.
surface tension
The high ___ of water allows the insect to remain on the surface instead of drowning.
2
The innermost electron shell of an atom can hold up to _____ electrons.
cell; skin cell
The lowest level of biological organization that can perform all the activities required for life is the... Ex: ___
8 neutrons in the nucleus.
The mass number of an atom is 15, and its atomic number is 7. The atom probably has...
protons and neutrons
The mass number of an element can be easily approximated by adding together the number of __________ in an atom of that element.
The nitrogen atom has a mass number of 14 and an atomic mass of approximately 14 daltons.
The nucleus of a nitrogen atom contains 7 neutrons and 7 protons. Which of the following is a correct statement concerning nitrogen?
protons
The number of ___ defines a chemical element.
a hydrogen bond
The slight negative charge at one end of one water molecule is attracted to the slight positive charge of another water molecule. What is this attraction called?
hydrogen bond
The slight negative charge at one end of one water molecule is attracted to the slight positive charge of another water molecule. What is this attraction called?
dissociation
The transfer of a hydrogen atom from one water molecule to another is referred to as ____.
polar
The unequal sharing of electrons within a water molecule helps to make the water molecule _____.
they share DNA because they share ancestry
The universal genetic language of DNA is common to virtually all organisms on Earth, however diverse. What is the best explanation for this fact?
sulfhydryl
Thiols are characterized by the presence of a ___ group.
2 electrons
To fill the valence shell, an electrically neutral, unbonded atom with atomic number 8 must add ...
True
True or False? Discovery science has contributed much to our understanding of nature without most of the steps of the so-called scientific method.
True
True or false: Ions may form by transferring an atomic nucleus (with or without electrons) to another molecule.
All the atoms lie in a plane.
Two C atoms form a double bond. Each C is bound to two H atoms. Which statement is true?
the same number of protons
Two atoms always represent the same element if they have ...
order, phylum, kingdom, class
Two species that belong to the same genus must also belong to the same...
exact location
We cannot know the ___ of an electron.
prokaryotes and eukaryotes
What are the two main types of cells?
the number of electrons in the outermost electron shell
What determines the types of chemical reactions that an atom participates in?
the shape of the flask
What did Pasteur change in his experiment to test the hypothesis of spontaneous generation?
Two atoms transfer or share outer electrons to complete their outer shells.
What happens when two atoms form a chemical bond?
An amino group.
What is NH2?
hypothesis
What is a tentative explanation that can be tested and is falsifiable?
31 daltons
What is the approximate atomic mass of an atom with 16 neutrons, 15 protons, and 15 electrons?
6
What is the atomic number of an atom that has 6 protons, 6 neutrons, and 6 electrons?
1+
What is the charge on a hydronium ion?
1-
What is the charge on a hydroxide ion?
the concentration of lemon juice is higher by a factor of 100 billion
What is the difference between H+ concentration in an acidic solution such as lemon juice (pH 2) and a basic solution such as household bleach (pH 13)?
kingdom, phylum, class, order, family, genus, species
What is the hierarchical organization of life from most to least inclusive?
pH 8
What is the pH of a solution with a hydrogen ion [H+] concentration of 10^-8 M?
pH 2
What is the pH of a solution with a hydroxyl ion [OH-] concentration of 10^-12 M?
molecule, cell, organ system, population, ecosystem, biosphere
What is the sequence that represents the hierarchy of biological organization from the least to the most complex level?
it can be supported or rejected through experimentation
What is true about a hypothesis?
none
What kind of effect does R-dopa have on Parkinson's disease?
hydrogen
What name is given to the bond between water molecules?
These atoms are isotopes.
What refers to atoms with the same atomic number but different atomic masses?
The number of protons is equal to the number of electrons.
What relationship is true of an uncharged atom?
a polar covalent bond.
What results from an unequal sharing of electrons between atoms?
flies were attacked less frequently
What results from the Zonosemata experiment support the sub-hypothesis that wing waving alone reduces predation by jumping spiders?
single (nonpolar) covalent
What type of bond joins the carbon atom to each of the hydrogen atoms?
1 L of 1.0 M NaCl
When an ionic compound such as sodium chloride (NaCl) is placed in water the component atoms of the NaCl crystal dissociate into individual sodium ions (Na+) and chloride ions (Cl-). In contrast, the atoms of covalently bonded molecules (e.g., glucose, sucrose, glycerol) do not generally dissociate when placed in aqueous solution. Which of the following solutions would be expected to contain the greatest number of particles (molecules or ions)?
structural formula.
When chemists and biologists want to show how atoms are bonded in a molecule, they usually use a ...
nonpolar covalent bonds.
When two atoms are equally electronegative, they will interact to form
covalent bond; equally
When two atoms of the same kind form a ___, they share electrons ___ because their electronegativity is the same.
O,N,C,H
Which answer correctly ranks the atoms in terms of decreasing electronegativity (the highest electronegativity first)?
The valence shell needs 8 electrons.
Which answer helps to explain why carbon atoms tend to make 4 covalent bonds?
sulfur
Which element would exhibit chemical behavior most like that of oxygen?
B
Which example illustrates a property that emerges at the community level? A. Photosynthesis takes place only when pigment molecules are arranged in a specific way in an intact chloroplast. B. Metabolic cooperation between prokaryotic cells forms a biofilm that allows bacterial colonies to transport nutrients and wastes. Biofilms may damage industrial equipment or cause tooth decay. C. Nitrogen cycling is the process by which nitrogen from the atmosphere and decomposed organic material are converted by soil bacteria to compounds that can be assimilated by plants.
-SH
Which functional group helps stabilize proteins by forming covalent cross-links within or between protein molecules?
Probability model
Which model most accurately represents the current view of the structure of the atom?
molecular formula
Which modeling method only gives information about the number and identity of atoms in a molecule?
They are both isotopes of phosphorus.
Which of the following best describes the relationship between the atoms described below? Atom 1 Atom 2 31:15 P 32:15 P
C2H4
Which of the following hydrocarbons has a double bond in its carbon skeleton?
They are nonpolar.
Which of the following is a false statement concerning amino groups?
D
Which of the following is a hydrophobic material? A. paper B. sugar C. pasta D. wax E. table salt
E
Which of the following is an example of qualitative data? A. The plant's height is 25 centimeters (cm). B. The contents of the stomach are mixed every 20 seconds. C. The six pairs of robins hatched an average of three chicks. D. The temperature decreased from 20°C to 15°C. E. The fish swam in a zig-zag motion.
C
Which of the following statements about the atoms in a water molecule is true? A. The hydrogen atom is very electronegative. B. Strong bonds can form between the hydrogen atoms in different water molecules. C. The oxygen atom in a water molecule has a partial negative charge. D. The oxygen and hydrogen atoms share electrons equally.
B
Which of the following statements concerning prokaryotic and eukaryotic cells is not correct? A. DNA, or deoxyribonucleic acid, is present in both prokaryotic cells and eukaryotic cells. B. Prokaryotic cells contain small membrane-enclosed organelles. C. Prokaryotic cells lack a membrane-bound nucleus. D. Eukaryotic cells contain a membrane-bound nucleus. E. DNA or deoxyribonucleic acid is present in the nucleus of eukaryotic cells.
C; it cannot be tested
Which of the following statements could not be supported or rejected by a scientific experiment? A. Grass is green because it contains chlorophyll. B. College students think football is more fun to watch than baseball. C. The first living cell on Earth came from outer space Why?
B
Which of the following statements is not true of scientific experiments? A. They must be well documented. B. They must occur under carefully controlled conditions found in a laboratory. C. They yield useful results regardless of whether the hypothesis is supported or rejected.
H2O and CH4, but not H2 and O2
Which of the following would be regarded as compounds?
C
Which of these is an organ system? A. stomach B. mucosa C. digestive D. gamete
H2O <==> H+ + OH-
Which of these is the correct equation for the dissociation of water?
adhesion
Which property of water allows a paper towel to pick up a puddle of water?
water's high heat of vaporization
Which property of water allows dogs to cool themselves by panting?
C
Which statement about a methyl functional group is correct? A. A methyl group may be negatively charged. B. A methyl group is polar. C. A methyl group consists of a carbon bonded to three hydrogen atoms.
E
Which statement is most useful in explaining why chemists assign atoms to chemical elements by counting protons? A. The proton's negative charge holds electrons in the atom. B. The nucleus doesn't change in stable isotopes. C. Protons at the atom's surface determine the atom's behavior. D. 99% of the atom's mass consists of protons. E. None of these. Elements are defined by the number of protons.
electrons determine the atom's size
Which statement is true of atoms?
The valence shell has higher energy than other occupied shells.
Which statement is true of the energy levels of electrons in shells?
electronegativity
Which term describes the degree to which an element attracts electrons?
anion and cation
Which terms describe two atoms when they form a bond in which electrons are completely transferred from one atom to the other?
Water has a large number of hydrogen bonds.
Why does water require so much energy to change its phase?
6.02 × 10^22
You have a freshly-prepared 0.1M solution of glucose in water. Each liter of this solution contains how many glucose molecules?
6.02 × 10^22
You have a freshly-prepared 1M solution of glucose in water. You carefully pour out a 100 mL sample of that solution. How many glucose molecules are included in that 100 mL sample?
Rotation
___ allows groups of atoms to change position while preserving the usual bond angles around each atom.
Ions
___ are charged atoms.
Geometric isomers
___ are molecules that differ in the arrangement of their atoms about a double bond.
Hydrogen bonds
___ are weaker than covalent bonds because they do not involve sharing of electrons, and they are weaker than ionic bonds because they involve the attraction of partial (not full) opposite charges.
Hydrogen bonds
___ can form between H and other highly electronegative atoms, such as O, if the atoms have strong partial charges.
O and N; H
___ can make hydrogen bonds, as can each ___ attached to O or N.
Phosphate
___ groups are a component of ATP.
Hydroxyl
___ groups are characteristic of alcohol.
Covalent bonds
___ hold atoms together because they fill shells without giving atoms much charge and bring electrons closer to protons.
Evaporative cooling
___ takes place when molecules with the greatest kinetic energy leave a fluid as gas molecules
hypotheses; theories
___ usually are relatively narrow in scope; ___ have broad explanatory power.