| Questions |
Answer |
Explanations |
|
31 Which radioisotope undergoes beta
decay and has
a half-life of less than 1 minute?
(1) Fr-220 (3)
N-16
(2)
K-42 (4) P-32 |
3 |
nuclear section- Use
table N to determine the decay
mode
|
|
32 Which set of symbols represents atoms
with valence
electrons in the same electron shell?
(1) Ba, Br,
Bi
(3) O, S, Te
(2) Sr, Sn,
I
(4) Mn, Hg, Cu |
2 |
All the elements are
in the same group |
|
33 When compared with the energy of an
electron in the
first shell of a carbon atom, the energy of an electron
in the second shell of a carbon atom is
(1) less
(2) greater
(3) the same |
2 |
more energy in the
higher energy levels |
|
34 What is the total number of electrons
found in an atom
of sulfur?
(1) 6 (2)
8 (3) 16
(4) 32 |
3 |
2-8-6
atoms are neutral (from Switzerland) |
|
35 Which electron configuration
represents the electrons
of an atom in an excited state?
(1) 2–8–1
(3) 2–8–17–6
(2) 2–8–6
(4) 2–8–18–5 |
3 |
Count the electrons
and check that element for the same configuration
note an electron has been
promoted in #3
|
|
36 The nucleus of an atom of cobalt-58
contains
(1) 27 protons and 31 neutrons
(2) 27 protons and 32 neutrons
(3) 59 protons and 60 neutrons
(4) 60 protons and 60 neutrons |
1 |
cobalt has an atomic
number of 27=protons
58 - 27- 31 neutrons
|
|
37 Which pair of formulas correctly
represents a molecular
formula and its corresponding empirical formula?
(1) C 2H2
and
CH
(3) C4H6
and CH
(2) C 3H4
and CH2
(4) C5H8
and C2H2 |
1 |
empirical formulas
are the lowest ratio of atoms in a formula |
|
38 Which substance is correctly paired
with its type of
bonding?
(1) NaBr—nonpolar covalent
(2) HCl—nonpolar covalent
(3) NH 3—polar
covalent
(4) Br 2—polar
covalent |
3 |
bonding- look at
the electronegativity differences
between the elements
|
|
39 A gas occupies a volume of 444 mL at
273 K and 79.0
kPa. What is the final kelvin temperature when
the volume of the gas is changed to 1880 mL and
the pressure is changed to 38.7 kPa?
(1) 31.5
K (3)
566 K
(2) 292
K
(4) 2360 K |
3 |
PV/T = PV/T
|
|
40 At STP, which of these substances is
most soluble in
H2O?
(1) CCl 4
(3) HCl
(2) CO 2
(4) N2
|
3 |
The polar substance dissolves in water
like dissolves like water is polar and so is HCl |