Exam 1 Practice Flashcards
What is the atomic number of an atom that has 6 protons, 6 neutrons, and 6 electrons?
12
18
1
0
6
6
Which of these refers to atoms with the same atomic number but different atomic masses?
These atoms have different numbers of protons.
These atoms have different numbers of electrons.
These atoms are different elements.
These atoms are isomers.
These atoms are isotopes.
These atoms are isotopes.
Fluorine’s atomic number is 9 and its atomic mass is 19. How many neutrons does fluorine have?
81
28
10
19
9
10
An uncharged atom of boron has an atomic number of 5 and an atomic mass of 11. How many protons does boron have?
0
5
6
16
11
5
Each element is unique and different from other elements because of the number of protons in the nuclei of its atoms. Which of the following indicates the number of protons in an atom’s nucleus?
atomic mass
atomic number
atomic weight
mass weight
mass number
atomic number
The innermost electron shell of an atom can hold up to _____ electrons.
18
8
1
32
2
2
Which of these relationships is true of an uncharged atom?
The number of neutrons is equal to the number of protons.
The atomic mass is equal to the number of electrons.
The atomic mass is equal to the atomic number.
The number of protons is equal to the number of electrons.
The number of electrons is equal to the number of neutrons.
The number of protons is equal to the number of electrons.
What determines the types of chemical reactions that an atom participates in?
its atomic mass
the number of electrons in the outermost electron shell
its atomic number
the number of protons it contains
the number of electrons in the innermost electron shell
the number of electrons in the outermost electron shell
What is the difference between starch and cellulose?
Starch is made of alpha glucose monomers. All oxygen bonds are down, which makes it curve. Used for energy STORAGE. Cellulose is made of beta glucose monomers. Oxygen bonds alternate, making it straight. Used for STRUCTURE.
A(n) _____ refers to two or more atoms held together by covalent bonds. molecule shell isotope ion community
Molecule
Atoms with the same number of protons but with different electrical charges _____. are different ions have different numbers of neutrons have different atomic masses have different atomic numbers are different isotopes
are different ions
In salt, what is the nature of the bond between sodium and chlorine?
hydrogen
ionic
hydrophobic
nonpolar
covalent
polar covalent
Ionic
What is the result of the animated process? a positively charged sodium ion and a negatively charged chlorine ion a negatively charged sodium ion and a negatively charged chlorine ion a positively charged sodium ion and a positively charged chlorine ion covalent bond formation a negatively charged sodium ion and a positively charged chlorine ion
a positively charged sodium ion and a negatively charged chlorine ion
An ionic bond involves _____. an attraction between ions of opposite charge the unequal sharing of an electron pair the sharing of a single pair of electrons water avoidance no atoms other than sodium and chlorine
an attraction between ions of opposite charge
Please refer to the figure to answer the following question.
Which drawing depicts the electron configuration of neon ( 2010Ne)?
A B C D E
E
What type of bond is joining the two hydrogen atoms?
hydrophilic ionic hydrophobic covalent hydrogen
Covalent
Many mammals control their body temperature by sweating. Which property of water is most directly responsible for the ability of sweat to lower body temperature?
the release of heat by the formation of hydrogen bonds
water’s change in density when it condenses
water’s high surface tension
the absorption of heat by the breaking of hydrogen bonds
water’s ability to dissolve molecules in the air
the absorption of heat by the breaking of hydrogen bonds
Water is able to form hydrogen bonds because
oxygen has a valence of 2.
each of the hydrogen atoms in a water molecule is weakly negative in charge.
the water molecule is shaped like a tetrahedron.
the oxygen atom in a water molecule has a weak positive charge.
the bonds that hold together the atoms in a water molecule are polar covalent bonds.
the bonds that hold together the atoms in a water molecule are polar covalent bonds.
Which of the following effects is produced by the high surface tension of water?
Lakes don’t freeze solid in winter, despite low temperatures.
Organisms resist temperature changes, although they give off heat due to chemical reactions.
A water strider can walk across the surface of a small pond.
The pH of water remains exactly neutral.
Water can act as a solvent.
A water strider can walk across the surface of a small pond.
Water’s high specific heat is mainly a consequence of the
absorption and release of heat when hydrogen bonds break and form.
high specific heat of oxygen and hydrogen atoms.
inability of water to dissipate heat into dry air.
fact that water is a poor heat conductor.
small size of the water molecules.
absorption and release of heat when hydrogen bonds break and form
Which type of bond must be broken for water to vaporize?
ionic bonds
hydrogen bonds
polar covalent bonds
nonpolar covalent bonds
covalent bonds
hydrogen bonds
Why does ice float in liquid water?
The liquid water molecules have more kinetic energy and thus support the ice. Ice always has air bubbles that keep it afloat.
The crystalline lattice of ice causes it to be denser than liquid water.
The ionic bonds between the molecules in ice prevent the ice from sinking.
Hydrogen bonds stabilize and keep the molecules of ice farther apart than the water molecules of liquid water.
Hydrogen bonds stabilize and keep the molecules of ice farther apart than the water molecules of liquid water.
What is the pH of a solution with a hydrogen ion [H+] concentration of 10-8 M?
pH 8
pH 6
pH 4
pH 2
pH 10
pH 8
If the pH of a solution is decreased from 9 to 8, it means that the
concentration of OH- has increased 10-fold (10X) compared to what it was at pH 9; concentration of H+ remains unchanged.
concentration of H+ has decreased to one-tenth (1/10) what it was at pH 9; concentration of OH-remains unchanged.
concentration of H+ has increased 10-fold (10X) compared to what it was at pH 9; concentration of OH- remains unchanged.
concentration of OH- has decreased to one-tenth (1/10) what it was at pH 9; concentration of H+remains unchanged.
concentration of H+ has increased 10-fold (10X) compared to what it was at pH 9 and concentration of OH– has decreased to one-tenth (1/10) what it was at pH 9.
concentration of H+ has increased 10-fold (10X) compared to what it was at pH 9 and concentration of OH– has decreased to one-tenth (1/10) what it was at pH 9.