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Questions
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Answer |
Explanations |
11 Lithium and potassium have similar chemical
properties because the atoms of both elements
have the same
(1) mass number
(2) atomic number
(3) number of electron shells
(4) number of valence electrons |
4 |
valence electrons determine the
chemical properties |
12 Which two substances are covalent compounds?
(1) C6H12O6(s) and KI(s)
(2) C6H12O(s) and HCl(g)
(3) KI(s) and NaCl(s)
(4) NaCl(s) and HCl(g) |
2 |
covalent nonmetal to nonmetal
NO METALS |
13 Which substance, when dissolved in water,
forms a solution that conducts an electric current?
(1) C2H5OH (3) C12H22O11
(2) C6H12O6 (4) CH3COOH |
4 |
the ionic one is an electrolyte |
 |
1 |
splitting an atom is fission |
15 Compared to a phosphorus atom, a P3 ion has
(1) more electrons and a larger radius
(2) more electrons and a smaller radius
(3) fewer electrons and a larger radius
(4) fewer electrons and a smaller radius |
1 |
more electrons and a larger radius
|
16 The balanced equation below represents a molecule
of bromine separating into two bromine atoms.
Br2-->Br + Br
What occurs during this change?
(1) Energy is absorbed and a bond is formed.
(2) Energy is absorbed and a bond is broken.
(3) Energy is released and a bond is formed.
(4) Energy is released and a bond is broken. |
2 |
the bond broke, which requires
energy (absorbs) |
17 Which substance can be decomposed by chemical
means?
(1) tungsten (3) krypton
(2) antimony (4) methane |
4 |
definition of a compound |
18 Bronze contains 90 to 95 percent copper and 5 to
10 percent tin. Because these percentages can
vary, bronze is classified as
(1) a compound (3) a mixture
(2) an element (4) a substance |
3 |
a mixture, they are not bonded
together, and vary in composition |
19 Compared to a 2.0 M aqueous solution of NaCl
at 1 atmosphere, a 3.0 M aqueous solution of
NaCl at 1 atmosphere has a
(1) lower boiling point and a higher freezing
point
(2) lower boiling point and a lower freezing
point
(3) higher boiling point and a higher freezing
point
(4) higher boiling point and a lower freezing
point |
4 |
the more concentrated
the higher the BP, and lower the FP |
20 In which reaction are electrons transferred from
one reactant to another reactant?
(1) 2Ca(s) + O2(g) =>2CaO(s)
(2) AgNO3(aq) + KCl(aq) =>AgCl(s) + KNO3(aq)
(3) HCl(aq) + NaOH(aq) =>NaCl(aq) + H2O(l)
(4) H3O+(aq) + OH-(aq) => 2H=O(l) |
1 |
defintion of REDOX
look for a free element (not Ion) |