Practice Quiz 1
You have 15 minutes to finish the quiz.
Q.1:
Which subatomic particles are associated with atomic mass?
electrons
protons
neutrons
all of the above
Q.2 :
How do ions of the same element differ from each other?
atomic number
atomic mass
number of protons
number of electrons
Q.3 :
What type of bond exists between Na and Cl in NaCl?
polar bond
ionic bond
covalent bond
crystal bond
Q.4 :
Which elementary particle determines largely the chemical properties of the element?
neutron
proton
electron
not determined by elementary particles
Q.5 :
The atomic mass of an element
is the combined mass of electrons, protons and neutrons of the element in grams
is the combined mass of electrons, protons and neutrons of the element in amu
is the weighted average of the masses (in amu) of all natural isotopes
all of the above
Q.6:
An isotope of an element has a
different number of protons
different number of electrons
different mass number
different atomic number
Q.7:
C-14 is
a stable isotope of C-12
emits alpha radiation
is formed in the upper atmosphere
has a half life of several days
Q.8:
Radioactive isotopes
have excess electrons
have excess protons
insufficient electrons
none of the above
Q.9 :
Oxygen has 8 protons. How many electrons are in its second shell (n-2)
2
6
8
16
Q.10 :
Why is the atomic mass (weight) of H = 1.008 amu and not exactly 1.000 amu as its mass number? Select the best explanation
atomic mass includes the mass of the electron
the atomic mass includes the weighted mass of isotopes
the mass number of an element is always lower than its atomic mass
because of the mass defect the atomic mass is larger than 1.000 amu
Q.11 :
Which statement is correct ?
covalent bonds are formed through electric attractions between the atoms
ionic bonds are based on the attractions of positively and negatively charged nuclei.
covalent bonds are weaker than ionic bonds
ionic bonds are the result of the transfer of one electron from one atom to another
Q.12 :
Which charaterizes best "Octet configuration"?
tendency of Br (electron configuration = 4s2, 4p5) to form a cation
driving force behind hybridization
tendency of Cl (electron configuration = 3s2, 3p5) to form an anion
the 8 electrons of the oxygen atom assume this configuration
Q.13 :
Carbon forms
ionic bonds
only covalent single bonds
covalent single, double and triple bonds
ionic bonds and covalent bonds
Q.14 :
Carbon (2s2, 2p2) forms single bonds such as in CH4 by
combining one 2s and one 2p-orbital to form two sp-hybrid orbitals
combining one 2s and two 2p-orbitals to form three sp2- hybrid orbitals
combining one 2s and three 2p-orbitals to form four sp3-hybrid orbitals
all of the above
Q.15 :
Which statement is
incorrect?
H-bonds are a stronger interaction than non polar interactions
C-N bonds and H-N bonds are both polar bonds
C-C bonds as well as C-H bonds are non-polar bonds
Non polar interactions are the weakest molecular interactions
all statements are correct
Q.16 :
Which statement about H-bonds is false?
H-bonds are formed between a H atom covalently bonded to O (N) and an O (N) atom of another molecule
H-bonds are most stable when there is a 180 degr. geometry between e.g. -OH and O=C-
H-bonds are more stable than polar interactions
all statements are correct
Q.17 :
Elements of the second group in the periodic table have their s orbitals filled with electrons, e.g. Mg: 3s2, Ca: 4s2, Sr: 5s2 . Which statement is correct about this group of elements?
they are chemically inert since their s-orbitals are filled
they have a tendency to give up two electrons in their compounds with e.g. Cl or Br
they have a tendency to take up two electrons in their compounds with e.g. Cl or Br
it takes more energy to remove a 5s electron from Sr, than a 3s electron from Mg
Q.18 :
A molecule is
a combination of two or more atoms
more stable than its isolated atoms
shares the electrons of its atoms
all ove the above
Q.19 :
Which pair of atoms have the most similar chemical properties?
H and He
H and D
C-12 and Si-28
C-13 and Si-28
Q.20 :
A covalent bond is likely to be polar if:
two atoms share the bonding electrons equally
a carbon atom is bonded to a hydrogen atom
one atom is capable of pulling the bond electrons more toward its side
none of the above statements is correct