Page 119 - Chemistry eBook

52 In the ground state, which noble gas has atoms with the same electron configuration as
a magnesium ion? [1]
53 Explain, in terms of electrons, why an atom of the metal in this reaction forms an ion that has a smaller radius than its atom. [1]
SamPart B–2
Base your answers to questions 54 through 56 on the iple Regents Questions
nformation below and on your knowledge of chemistry.
Allow a total of 15 credits for this part. The student must answer all questions in this part.
The balanced equation below represents a reaction.
51 [1] Allow 1 credit for __3_ Mg(s) 􏰀 ___ N2(g) → ___ Mg3N2(s). O2(g) 􏰀 energy → O(g) 􏰀 O(g)
Allow credit even if the coefficient “1” is written in front of N2(g) and/or Mg3N2(s).
54 Identify the type of chemical bond in a molecule of the reactant. [1]
52 [1] Allow 1 credit for Ne or neon.
55 In the space in your answer booklet, draw a Lewis electron-dot diagram of one oxygen
atom. [1]
53 [1] Allow 1 credit. Acceptable responses include, but are not limited to:
56 Explain, in terms of bonds, why energy is absorbed during this reaction. [1]
The reactant is what you start out with, and the product is what you end up with.
An atom of magnesium loses its outer shell electrons to form the Mg2+ ion.
54 [1]
The electron configuration of a magnesium atom is 2-8-2, and the electron configuration of the magnesium ion is 2-8.
An atom of the metal loses elecJturonseto2fo0rm13the#ion5. 4-56
Allow 1 credit. Acceptable responses include, but are not limited to: covalent
P.S./Chem.–June ’13
double covalent
Answer
nonpolar [8] 54. Nonpdoulbaler covalent
Explanation: Nonpolar covalent means that two of the same element bonds together.
55 [1] Allow 1 credit.
55. Examples of 1-credit responses: 56. When bonds are broken,
O
O
energy is absorbed.
XX
X O X X
UNIT 4: BONDING © 119