Page 84 - Chemistry eBook

Which element is not present in the mixture?
(3) X (4) Z
34 Whic electr
(1) 2 (2) 2
35 Give sodi Whic
by thi
(1) d (2) si
(1) A (2) D
Sample Regents Questions
32 What is the overall charge of an ion that has 12 protons, 10 electrons, and 14 neutrons?
(1) 2􏰁 (3) 4􏰁 (2) 2􏰀 (4) 4􏰀
33 As the elements in Period 3 are considered in
June 2013 #32
order of increasing atomic number, there is a general decrease in
(1) atomic mass
(2) atomic radius (3) electronegativity
Choice #2 (4) first ionization energy
Explanation: The atom has 12 protons and 10 electrons. The number of protons
in an atom is supposed to match the number of electrons, but the numbers don’t match. There are 2 fewer electrons than protons. It looks like the atom gave away 2 electrons. The symbol for giving away 2 electrons is +2. (Remember: it’s a “Pp.So.s/iCthiveem”.–tJhuineg’t1o3 give.) [5]
Answer
h
- -
n
h
o n
84 © UNIT 3: PERIODIC TABLE OF ELEMENTS