Page 79 - Chemistry eBook

Answer all questions in this part.
statement or question, record on your separate answer sheet the number of the given, best completes the statement or answers the question. Some questions
Edition Reference Tables for Physical SettinSga/mCphlemRisetgreyn. ts Questions
has two electrons in 35 s in its second shell.
of protons in the
7 8
ed state could have
2-8-17-7 2-8-17-8
natural abundances urring isotopes of
le below. Choice #2
Which general trend is found in Period 3 as the elements are considered in order of increasing atomic number?
(1) increasing atomic radius
(2) increasing electronegativity
(3) decreasing atomic mass
(4) decreasing first ionization energy
June 2012 #35
O
36 Given the formula for a compound:
C OCCO
Answer
HNNH C
opes
Explanation: We can figure out the answer just from Natural Reffy. O
s
a. Find Period 3 on the Periodic Table. The atomic numbers Which molecular formula and empirical formula
Abundance
(%)
7.5 92.5
be used to deter-
of Period 3 are 11-18.
“Try the other choices. You will see that Reffy doesn’t allow any of those options.”
represent this compound?
b. Find the electronegativity of atomic numbers 11-18 on
Table S. (1) C2HNO2 and CHNO (2) C HNO and C HNO
2 2 2
2
They are 0.9, 1.3, 1.6, 1.9, and 2.2. The numbers are increasing!
(3) C4H2N2O4 and CHNO (4) C4H2N2O4 and C2HNO2
n
) )
t
) )
b
UNIT 3: PERIODIC TABLE OF ELEMENTS © 79
n hium?