Question

name ______________________ period ________
isotopes, ions, and atoms worksheet 2

atomic #	mass #	# p⁺	# e⁻	# n⁰	charge	symbol
2)	75		36	42
3)		51	54	79
4) 99	252		96
5)						$_{82}^{208}\ce{pb^{2+}}$
6)		52		76	-2
7)	113	48	49
8) 42	98				+6
9)						$_{7}^{17}\ce{n^{3-}}$
10)	209	83			+5
11)						$_{46}^{110}\ce{pd}$
12)	124	50			+4
13)	79	35			-1
14) 60	148		58

Answer:

To solve the problems in the "Isotopes, Ions, and Atoms Worksheet 2", we use the following relationships:

• Atomic number (\(Z\)) = number of protons (\(p^+\))
• Mass number (\(A\)) = number of protons (\(p^+\)) + number of neutrons (\(n^0\))
• Charge = number of protons (\(p^+\)) − number of electrons (\(e^-\)) (so \(e^- = p^+ - \text{charge}\))

Problem 1:

Given: Atomic # = 14, \(n^0 = 16\), charge = +4

• Step 1: \(p^+ = \text{Atomic #} = 14\)
• Step 2: \(A = p^+ + n^0 = 14 + 16 = 30\)
• Step 3: \(e^- = p^+ - \text{charge} = 14 - 4 = 10\)
• Symbol: \(_{14}^{30}\text{Si}^{4+}\) (Si is element 14)

Problem 2:

Given: \(A = 75\), \(e^- = 36\), \(n^0 = 42\)

• Step 1: \(p^+ = A - n^0 = 75 - 42 = 33\) (Atomic # = 33)
• Step 2: Charge = \(p^+ - e^- = 33 - 36 = -3\)
• Symbol: \(_{33}^{75}\text{As}^{3-}\) (As is element 33)

Problem 3:

Given: \(p^+ = 51\), \(e^- = 54\), \(n^0 = 79\)

• Step 1: Atomic # = \(p^+ = 51\)
• Step 2: \(A = p^+ + n^0 = 51 + 79 = 130\)
• Step 3: Charge = \(p^+ - e^- = 51 - 54 = -3\)
• Symbol: \(_{51}^{130}\text{Sb}^{3-}\) (Sb is element 51)

Problem 4:

Given: Atomic # = 99, \(A = 252\), \(e^- = 96\)

• Step 1: \(p^+ = \text{Atomic #} = 99\)
• Step 2: \(n^0 = A - p^+ = 252 - 99 = 153\)
• Step 3: Charge = \(p^+ - e^- = 99 - 96 = +3\)
• Symbol: \(_{99}^{252}\text{Es}^{3+}\) (Es is element 99)

Problem 5:

Given: Symbol = \(_{82}^{208}\text{Pb}^{2+}\)

• Step 1: \(p^+ = \text{Atomic #} = 82\)
• Step 2: \(A = 208\)
• Step 3: \(n^0 = A - p^+ = 208 - 82 = 126\)
• Step 4: \(e^- = p^+ - \text{charge} = 82 - 2 = 80\)
• Charge = +2

Problem 6:

Given: \(p^+ = 52\), \(n^0 = 76\), charge = -2

• Step 1: Atomic # = \(p^+ = 52\)
• Step 2: \(A = p^+ + n^0 = 52 + 76 = 128\)
• Step 3: \(e^- = p^+ - \text{charge} = 52 - (-2) = 54\)
• Symbol: \(_{52}^{128}\text{Te}^{2-}\) (Te is element 52)

Problem 7:

Given: \(A = 113\), \(p^+ = 48\), \(e^- = 49\)

• Step 1: Atomic # = \(p^+ = 48\)
• Step 2: \(n^0 = A - p^+ = 113 - 48 = 65\)
• Step 3: Charge = \(p^+ - e^- = 48 - 49 = -1\)
• Symbol: \(_{48}^{113}\text{Cd}^{-}\) (Cd is element 48)

Problem 8:

Given: Atomic # = 42, \(A = 98\), charge = +6

• Step 1: \(p^+ = \text{Atomic #} = 42\)
• Step 2: \(n^0 = A - p^+ = 98 - 42 = 56\)
• Step 3: \(e^- = p^+ - \text{charge} = 42 - 6 = 36\)
• Symbol: \(_{42}^{98}\text{Mo}^{6+}\) (Mo is element 42)

Problem 9:

Given: Symbol = \(_{7}^{17}\text{N}^{3-}\)

• Step 1: \(p^+ = \text{Atomic #} = 7\)
• Step 2: \(A = 17\)
• Step 3: \(n^0 = A - p^+ = 17 - 7 = 10\)
• Step 4: \(e^- = p^+ - \text{charge} = 7 - (-3) = 10\)
• Charge = -3

Problem 10:

Given: \(A = 209\), \(p^+ = 83\), charge = +5

• Step 1: Atomic # = \(p^+ = 83\)
• Step 2: \(n^0 = A - p^+ = 209 - 83 = 126\)
• Step 3: \(e^- = p^+ - \text{charge} = 83 - 5 = 78\)
• Symbol: \(_{83}^{209}\text{Bi}^{5+}\) (Bi is element 83)

Problem 11:

Given: Symbol = \(_{46}^{110}\text{Pd}\)

• Step 1: \(p^+ = \text{Atomic #} = 46\)
• Step 2: \(A = 110\)
• Step 3: \(n^0 = A - p^+ = 110 - 46 = 64\)
• Step 4: Charge = \(p^+ - e^-\). Since it’s neutral (\(\text{Pd}\) not an ion), \(e^- = p^+ = 46\), charge = 0

Problem 12:

Given: \(A = 124\), \(p^+ = 50\), charge = +4

• Step 1: Atomic # = \(p^+ = 50\)
• Step 2: \(n^0 = A - p^+ = 124 - 50 = 74\)
• Step 3: \(e^- = p^+ - \text{charge} = 50 - 4 = 46\)
• Symbol: \(_{50}^{124}\text{Sn}^{4+}\) (Sn is element 50)

Problem 13:

Given: \(A = 79\), \(p^+ = 35\), charge = -1

• Step 1: Atomic # = \(p^+ = 35\)
• Step 2: \(n^0 = A - p^+ = 79 - 35 = 44\)
• Step 3: \(e^- = p^+ - \text{charge} = 35 - (-1) = 36\)
• Symbol: \(_{35}^{79}\text{Br}^{-}\) (Br is element 35)

Problem 14:

Given: Atomic # = 60, \(A = 148\), \(e^- = 58\)

• Step 1: \(p^+ = \text{Atomic #} = 60\)
• Step 2: \(n^0 = A - p^+ = 148 - 60 = 88\)
• Step 3: Charge = \(p^+ - e^- = 60 - 58 = +2\)
• Symbol: \(_{60}^{148}\text{Nd}^{2+}\) (Nd is element 60)

Final Table (Filled):

Atomic #	Mass #	# \(p^+\)	# \(e^-\)	# \(n^0\)	charge	Symbol
33	75	33	36	42	-3	\(_{33}^{75}\text{As}^{3-}\)
51	130	51	54	79	-3	\(_{51}^{130}\text{Sb}^{3-}\)
99	252	99	96	153	+3	\(_{99}^{252}\text{Es}^{3+}\)
82	208	82	80	126	+2	\(_{82}^{208}\text{Pb}^{2+}\)
52	128	52	54	76	-2	\(_{52}^{128}\text{Te}^{2-}\)
48	113	48	49	65	-1	\(_{48}^{113}\text{Cd}^{-}\)
42	98	42	36	56	+6	\(_{42}^{98}\text{Mo}^{6+}\)
7	17	7	10	10	-3	\(_{7}^{17}\text{N}^{3-}\)
83	209	83	78	126	+5	\(_{83}^{209}\text{Bi}^{5+}\)
46	110	46	46	64	0	\(_{46}^{110}\text{Pd}\)
50	124	50	46	74	+4	\(_{50}^{124}\text{Sn}^{4+}\)
35	79	35	36	44	-1	\(_{35}^{79}\text{Br}^{-}\)
60	148	60	58	88	+2	\(_{60}^{148}\text{Nd}^{2+}\)

(Note: Symbols are based on element atomic numbers. For example, atomic #14 is Si, #33 is As, etc.)