10. **write the complete symbol for an atom with the following characteristics:\n|characteristics|atomic…
10. **write the complete symbol for an atom with the following characteristics:\n|characteristics|atomic symbol (include atomic #, mass #, and charge)|\n|----|----|\n|a. neutral atom that contains 19 electrons and 20 neutrons|\n|b. nitrogen atom with 8 neutrons and 10 electrons|\n|c. neutral isotope of (b) with 9 neutrons|\n|d. contains 20 protons, 19 electrons, and 22 neutrons|\n|e. neutral iodine atom with 181 subatomic particles in its nucleus|\n11. use the data table below to answer the following questions. the two isotopes are of unknown element j.\n|isotope|atomic mass (amu)|natural abundance|\n|----|----|----|\n|1|120.90|57.21%|\n|2|122.90|42.79%|\na. *calculate the atomic mass of this element and determine its identity. make sure to use significant figures!\nb. based on your answer above, complete the table below.\n|isotope|nuclear symbol|isotope name|\n|----|----|----|\n|1|\n|2|
Answer
10.
a.
Explanation:
Step1: Determine the atomic number
For a neutral atom, number of electrons = number of protons. Given 19 electrons, atomic number (Z = 19), which is potassium (K).
Step2: Calculate the mass number
Mass number (A=) number of protons+number of neutrons. Protons = 19, neutrons = 20, so (A=19 + 20=39). Charge (q = 0) (neutral atom). The atomic symbol is (\ce{_{19}^{39}K}).
b.
Explanation:
Step1: Determine the atomic number of nitrogen
Nitrogen has an atomic number (Z = 7).
Step2: Calculate the mass number
Mass number (A=) number of protons+number of neutrons. Protons = 7, neutrons = 8, so (A=7 + 8 = 15).
Step3: Determine the charge
There are 10 electrons and 7 protons, so the charge (q=7 - 10=- 3). The atomic symbol is (\ce{_{7}^{15}N^{3 -}}).
c.
Explanation:
Step1: Recall the atomic number of nitrogen
Atomic number of nitrogen (Z = 7) (unchanged as it's still nitrogen).
Step2: Calculate the mass number
Protons = 7, neutrons = 9, so (A=7+9 = 16). Charge (q = 0) (neutral atom). The atomic symbol is (\ce{_{7}^{16}N}).
d.
Explanation:
Step1: Identify the element by atomic number
With 20 protons, the element is calcium (Ca) since (Z = 20).
Step2: Calculate the mass number
Protons = 20, neutrons = 22, so (A=20 + 22=42).
Step3: Determine the charge
There are 20 protons and 19 electrons, so the charge (q=20 - 19 = 1). The atomic symbol is (\ce{_{20}^{42}Ca^{+}}).
e.
Explanation:
Step1: Determine the atomic number of iodine
Iodine has an atomic number (Z = 53).
Step2: Calculate the number of neutrons
The number of sub - atomic particles in the nucleus is the sum of protons and neutrons. Protons = 53 (for iodine), and total sub - atomic particles in the nucleus (=181). So number of neutrons (n=181 - 53 = 128). Mass number (A=53+128 = 181). Charge (q = 0) (neutral atom). The atomic symbol is (\ce{_{53}^{181}I}).
11.
a.
Explanation:
Step1: Use the formula for average atomic mass
The formula for the average atomic mass (M) of an element with two isotopes is (M = M_1\times%_1+M_2\times%_2), where (M_1) and (M_2) are the atomic masses of the isotopes and (%_1) and (%_2) are their natural abundances as decimals. (%_1=0.5721), (M_1 = 120.90) amu, (%_2=0.4279), (M_2 = 122.90) amu. [ \begin{align*} M&=(120.90\times0.5721)+(122.90\times0.4279)\ &=120.90\times0.5721+122.90\times(1 - 0.5721)\ &=120.90\times0.5721+122.90\times0.4279\ &=69.16689+52.58891\ &=121.7558\approx121.76\text{ amu} \end{align*} ] The element with an average atomic mass of approximately 121.76 amu is antimony (Sb).
Answer:
The atomic mass of the element is 121.76 amu and the element is antimony (Sb).
b.
For isotope 1: Nuclear symbol: (\ce{{51}^{121}Sb}) (since (Z = 51) for antimony and (A = 120.90\approx121)), isotope name: Antimony - 121. For isotope 2: Nuclear symbol: (\ce{{51}^{123}Sb}) (since (Z = 51) for antimony and (A = 122.90\approx123)), isotope name: Antimony - 123.
Answer:
Isotope 1: Nuclear symbol (\ce{{51}^{121}Sb}), Isotope name Antimony - 121 Isotope 2: Nuclear symbol (\ce{{51}^{123}Sb}), Isotope name Antimony - 123