Quiz and Exam 1
Which one of the atoms would be most likely to form a cation with a charge of +1? A) 1 valence electron B) 4 valence electrons C) 5 valence electrons D) 8 valence electrons E) 7 valence electrons
1 valence electron
One liter of a solution of pH 2 has how many more hydrogen ions (H+) than 1 L of a solution of pH 6?
10,000 times more
Measurements show that the pH of a particular lake is 4.0. What is the hydrogen ion concentration of the lake?
10^-4 M
What is the hydrogen ion (H+) concentation of a solution of pH 8?
10^-8 M
How many electrons are present in Phosphorus 3+ atom?
12
The atomic number of each atom to the left of each of the elements below. Which of the atoms have the same valence as carbon (C atomic number is 6)?
12Si silicon
What coefficients must be placed in the following blanks so that all atoms are accounted for in the products? C6H12O6 → _____ C2H6O + _____ CO2 a. 3; 1 b. 2; 2 c. 1; 3 d. 1; 2 e. 1; 1
2;2
What is the maximum number of hydrogen atoms that can be covalently bonded in a molecule containing two atoms?
3
How many electrons does carbon share in order to complete its valence shell
4
How many electrons will a single atom of sulfur with no charge and no bonds have its valence shell?
6
Which drawing in the figure above is of the electron configuration of a sodium 11Na+ ion?
8 on the outside two on the inside.
What results from the chemical reaction in the illustration? The reactants have no charge.
A cation with a net charge of +1 and an anion with a net charge of -1
Which of the following effects can occur because of the high surface tension of water?
A raft spider can walk across the surface of a small pond.
Refer to the following figure to answer the questions below. 3 H2 + N2 -> 2NH3 Which of the following is true for the reaction?
Ammonia is being formed and decomposed simultaneously.
Which of the following order in terms of the hierarchy of the organization?
Biosphere -> Ecosystem -> Community -> Population -> Organism
Which hydrocarbon has a double bond in its carbon skeleton?
C2H4
What is the difference between covalent bonds and ionic bonds
Covalent bonds involve the sharing of pairs of electrons between atoms; ionic bonds involve the sharing of single electron between atoms.
Which of the following solutions has the greatest concentration of Hydrogen ions [H+]?
Gastric juice at pH=2
If the cytoplasm of a cell is at pH 7, and the mitochondrial matrix is at pH 8, this means that
H+ ions is tenfold higher in the cytoplasm than in the mitochondrial matrix
What element does not prefer to react with other elements?
Helium
Trace elements are those required by an organism in only minute quantities. Which of the following is a trace element that is required by humans and other vertebrates, but not by other organisms such as bacteria or plants?
Iodine
A solution contains (10^-7) mole of H+ per liter (concentration). Which of the following best describes this solution?
Neutral
Eukaryotic cells differ from prokaryotic cells in that eukaryotic cells have
Organelles
Which of the following solutions has the greatest concentration of hydroxyl ions [OH-]
Seawater at pH=8
Which statement is true of all atoms that are anions?
The atoms has more electrons than protons.
What determines if a molecule is polar or non polar?
The differences in the electronegativities of the atoms
Which of the following statements is true about buffer solutions?
They maintain a relatively constant pH when either acids or bases are added to them.
What resutls from an unequal sharing of electron between atoms?
a polar covalent bond
Buffers are substances that help resist shifts in pH by
both donating a H+ to a solution when bases are added, and accepting H+ when acids are added.
Water molecule are able to form hydrogen bonds with
compounds that have polar covalent bonds.
If the pH of a solution is increased from pH 5 to pH 7, it means that the
concentration of OH- is 100 times greater than what it was at pH 5.
A carbon atom is most likely to form what kind of bond(s) with other atoms?
covalent
A(n) ___ has charge but negligible mass, whereas a(n) ___ has mass but no charge.
electron; neutron
Testosterone and estradiol are male and female sex hormones, respectively, in many vertebrates. In what way(s) do these molecules differ from each other? Testosterone and estradiol
have different groups attached to the same carbon skeleton
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
Which of the following explains most specifically the attraction of water molecules to one another?
hydrogen bond
Which type of bond must be broken for water to vaporize?
hydrogen bond
If the cytoplasm of a cell is at pH 7, and the mitochondrial matrix is at pH 8, then the concentration of H+ ions
is 10 times higher in the cytoplasm than in the mitochondrial matrix
Which drawing in the figure above depicts the electron configuration of an atom capable of forming three covalent bonds with other atoms?
it has 5 electron on the outside and 2 inside.
You are asked to indicate the type and number of atoms in a molecule. Which representation would work best?
molecular formula
which of the following is a correct sequence of levels in life's hierarchy, proceeding downwards from an individual animal?
nervous system, brain, nervous tissue, nerve cell
a solution contains (10^-7) mole of hydroxide ions [OH-] per liter. Which of the following best describes this solution?
neutral
When two atoms are equally electronegative, they will interact to form
nonpolar covalent bonds
Carbon-14 is the same
number of protons but more neutrons that carbon-12
Compared with 31P, the radioactive isotope 32P has
one more neutron
A covalent chemical bond is one in which
outer-shell electrons of two atoms are shared so as to satisfactorily fill the outer electron shell of both atoms.
What is the pH of a solution with a hydroxyl ion [OH-] concentration of 10^-12 M
pH 2
In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by
polar covalent bonds
A localized group of organisms that belong to the same species is called a
population
Based on your knowledge of the polarity of water molecules, the solute molecule depicted here is most likely
positively charged
To act as an effective coolant in a car's radiator, a substance has to have the capacity to absorb a great deal of heat. You have a reference book with tables listing the physical properties of many liquids. In choosing a coolant for your car, which table would you check first?
specific heat
Knowing just the atomic mass of an element allows inferences about which of the following?
the number of protons plus (+) neutrons in the element
a group of cells that work together to carry out a similar function is known as a(n)
tissue
Which of the following is a hydrophobic material?
wax
When are atoms most stable?
when all of the electron orbitals in the valence shell are filled