Chlorine has seven electrons in its valence shell. The number of electrons it must gain to complete its
valence shell is:
one.
two.
three.
seven.
eight.
Which of the following elements is NOT responsible for a significant portion of the mass of living
organisms?
C
N
O
H
S
Isotopes differ from each other with respect to the number of:
protons only.
electrons only.
neutrons only.
both protons and
electrons.
both neutrons and
protons.
Use the figure below to answer the co
esponding question.
The type of bond illustrated is:
an ionic bond.
a polar bond.
a single covalent bond.
a hydrogen bond.
a double covalent
ond.
Which covalent bond involves only 2 electrons (1 pair):
single
double
triple
single and
double.
single and triple.
A pH of 4 is __________ times more __________ than a pH of 7.
3; basic
3; acidic
1000;
neutral
1000; basic
1000; acidic
Which of the following choices co
ectly identifies a reactant in the following chemical equation?
C​6​H​12​O​6 ​+ O​2​ --> 6CO​2​ + 6H​2​O + energy
C​6​H​12​O​6
O​2
H​2​O
CO​2
Both (a) and
(b)
A solution having a pH of 6 would:
have equal concentrations of hydrogen ions and hydroxide ions.
have a higher concentrations of hydroxide ions than hydrogen
ions.
be slightly acidic.
be slightly basic.
be neutral.
The difference between an electrically neutral atom and an ion is that:
an ion has an unequal number of protons and electrons, while an atom has an equal
number.
an ion has an equal number of protons and electrons, while an atom has an unequal
number.
an atom has an unequal number of neutrons and protons, while an ion has an equal
number.
an atom has its electrons in o
itals, while an ion has its electrons in its nucleus.
an atom must have an equal number of neutrons and electrons, while an ion does not.
A stalk of celery is placed in a solution of blue colored dye. After one hour, the leaves have blue fluid in
their veins. Which property of water is being demonstrated?
adhesion and cohesion
evaporation and cooling
lower density as a solid than as a
liquid
high specific heat
surface tension