MCC BIO 181 Exam 1 with all Correct & 100% Verified
Answers| Actual Complete Exam |Already Graded A+
Why is each element unique and different from other elements in chemical properties? ✔Correct
Answer--Each element has a unique number of protons in its nucleus.
An atom with atomic number 12 would have what type of chemical behavior in bonding with other
elements? ✔Correct Answer--It would form ions with a +2 charge.
In a reaction that has reached chemical equilibrium ✔Correct Answer--All of the reactants have
been converted to the products of the reaction.
The rate of the forward reaction is equal to the rate of the reverse reaction.
From its atomic number of 15, it is possible to predict that the phosphorus atom has ✔Correct
Answer--15 protons and 15 electrons.
The attraction of a particular kind of atom for the electrons of a covalent bond is called its
✔Correct Answer--electronegativity.
electronegativity increase from left to right of the periodic table.
Fluorine has an atomic number of 9 and a mass number of 19. How many electrons are needed to
complete the valence shell of a fluorine atom? ✔Correct Answer--1
Which of the following explains most specifically the attraction of water molecules to one another?
✔Correct Answer--hydrogen bonds
How many electron pairs are shared between carbon atoms in a molecule that has the formula
C2H4? ✔Correct Answer--2
A covalent chemical bond is one in which ✔Correct Answer--outer-shell electrons of two atoms are
shared so as to satisfactorily fill the outer electron shells of both atoms.
Atoms whose outer electron shells contain 8 electrons tend to ✔Correct Answer--be both
chemically inert and gaseous at room temperature.
What bond or interaction would be difficult to disrupt when compounds are put into water?
✔Correct Answer--covalent bond
Molybdenum has an atomic number of 42. Several common isotopes exist, with mass numbers of 92,
94, 95, 96, 97, 98, and 100. How many neutrons can these isotopes contain? ✔Correct Answer--
Molybdenum atoms can have between 50 and 58 neutrons.
One difference between carbon-12 (C) is that carbon-14 (C) has ✔Correct Answer--two more
neutrons than carbon-12.
3 H2 + N2 ↔ 2 NH3 ✔Correct Answer--Ammonia is being formed and decomposed.
, 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? ✔Correct Answer--carbon, hydrogen,
nitrogen, oxygen
H2O and CH4 are both examples of ✔Correct Answer--compounds
A covalent bond is likely to be polar when ✔Correct Answer--one of the atoms sharing electrons is
much more electronegative than the other atom.
A covalent chemical bond is one in which ✔Correct Answer--outer-shell electrons of two atoms are
shared so as to satisfactorily fill the outer electron shells of both atoms.
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? ✔Correct Answer--a hydrogen bond
The molecular weight of water is 18 daltons. What is the molarity of 1 liter of pure water? (Hint:
What is the mass of 1 liter of pure water?) ✔Correct Answer--55.6 M
What is the pH of a 1 millimolar NaOH solution? ✔Correct Answer--pH 11
In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by
✔Correct Answer--polar covalent bonds.
Temperature usually increases when water condenses. Which behavior of water is most directly
responsible for this phenomenon? ✔Correct Answer--the release of heat by the formation of
hydrogen bonds
NaOH is considered to be ✔Correct Answer--a strong base (alkali) and will ionize completely in
water
gastric juice at pH 2 would ✔Correct Answer--require the greatest amount of base to be added to
bring the solution to neutral pH
One liter of a solution of pH 9 has how many more hydroxyl ions (OH-) than 1 L of a solution of pH 4?
✔Correct Answer--100,000 times more
You have a freshly prepared 0.1 M solution of glucose in water. Each liter of this solution contains
how many glucose molecules? ✔Correct Answer--6.02 × 1022
If the pH of a solution is increased from pH 5 to pH 7, it means that the ✔Correct Answer--
concentration of OH- is 100 times greater than what it was at pH 5.
Why does ice float in liquid water? ✔Correct Answer--Hydrogen bonds stabilize and keep the
molecules of ice farther apart than the water molecules of liquid water.
How many molecules of glycerol (C3H8O3; molecular mass = 92) would be present in 1 L of a 1 M
glycerol solution? ✔Correct Answer--6.02 × 1023
In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by
✔Correct Answer--polar covalent bonds.
Answers| Actual Complete Exam |Already Graded A+
Why is each element unique and different from other elements in chemical properties? ✔Correct
Answer--Each element has a unique number of protons in its nucleus.
An atom with atomic number 12 would have what type of chemical behavior in bonding with other
elements? ✔Correct Answer--It would form ions with a +2 charge.
In a reaction that has reached chemical equilibrium ✔Correct Answer--All of the reactants have
been converted to the products of the reaction.
The rate of the forward reaction is equal to the rate of the reverse reaction.
From its atomic number of 15, it is possible to predict that the phosphorus atom has ✔Correct
Answer--15 protons and 15 electrons.
The attraction of a particular kind of atom for the electrons of a covalent bond is called its
✔Correct Answer--electronegativity.
electronegativity increase from left to right of the periodic table.
Fluorine has an atomic number of 9 and a mass number of 19. How many electrons are needed to
complete the valence shell of a fluorine atom? ✔Correct Answer--1
Which of the following explains most specifically the attraction of water molecules to one another?
✔Correct Answer--hydrogen bonds
How many electron pairs are shared between carbon atoms in a molecule that has the formula
C2H4? ✔Correct Answer--2
A covalent chemical bond is one in which ✔Correct Answer--outer-shell electrons of two atoms are
shared so as to satisfactorily fill the outer electron shells of both atoms.
Atoms whose outer electron shells contain 8 electrons tend to ✔Correct Answer--be both
chemically inert and gaseous at room temperature.
What bond or interaction would be difficult to disrupt when compounds are put into water?
✔Correct Answer--covalent bond
Molybdenum has an atomic number of 42. Several common isotopes exist, with mass numbers of 92,
94, 95, 96, 97, 98, and 100. How many neutrons can these isotopes contain? ✔Correct Answer--
Molybdenum atoms can have between 50 and 58 neutrons.
One difference between carbon-12 (C) is that carbon-14 (C) has ✔Correct Answer--two more
neutrons than carbon-12.
3 H2 + N2 ↔ 2 NH3 ✔Correct Answer--Ammonia is being formed and decomposed.
, 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? ✔Correct Answer--carbon, hydrogen,
nitrogen, oxygen
H2O and CH4 are both examples of ✔Correct Answer--compounds
A covalent bond is likely to be polar when ✔Correct Answer--one of the atoms sharing electrons is
much more electronegative than the other atom.
A covalent chemical bond is one in which ✔Correct Answer--outer-shell electrons of two atoms are
shared so as to satisfactorily fill the outer electron shells of both atoms.
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? ✔Correct Answer--a hydrogen bond
The molecular weight of water is 18 daltons. What is the molarity of 1 liter of pure water? (Hint:
What is the mass of 1 liter of pure water?) ✔Correct Answer--55.6 M
What is the pH of a 1 millimolar NaOH solution? ✔Correct Answer--pH 11
In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by
✔Correct Answer--polar covalent bonds.
Temperature usually increases when water condenses. Which behavior of water is most directly
responsible for this phenomenon? ✔Correct Answer--the release of heat by the formation of
hydrogen bonds
NaOH is considered to be ✔Correct Answer--a strong base (alkali) and will ionize completely in
water
gastric juice at pH 2 would ✔Correct Answer--require the greatest amount of base to be added to
bring the solution to neutral pH
One liter of a solution of pH 9 has how many more hydroxyl ions (OH-) than 1 L of a solution of pH 4?
✔Correct Answer--100,000 times more
You have a freshly prepared 0.1 M solution of glucose in water. Each liter of this solution contains
how many glucose molecules? ✔Correct Answer--6.02 × 1022
If the pH of a solution is increased from pH 5 to pH 7, it means that the ✔Correct Answer--
concentration of OH- is 100 times greater than what it was at pH 5.
Why does ice float in liquid water? ✔Correct Answer--Hydrogen bonds stabilize and keep the
molecules of ice farther apart than the water molecules of liquid water.
How many molecules of glycerol (C3H8O3; molecular mass = 92) would be present in 1 L of a 1 M
glycerol solution? ✔Correct Answer--6.02 × 1023
In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by
✔Correct Answer--polar covalent bonds.
