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Step-by-step solution for: SOLUTION: Basic atomic structure worksheet - Studypool
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Step-by-step solution for: SOLUTION: Basic atomic structure worksheet - Studypool
Let’s go step by step to solve each part of the worksheet.
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Question 10: Name the element which has the following numbers of particles
Remember: The number of protons tells you what element it is. That’s the atomic number (Z). Electrons can change if it’s an ion, but protons define the element. Neutrons help find the mass number (A = protons + neutrons), but not the identity.
a. 26 electrons, 29 neutrons, 26 protons
→ Protons = 26 → Element with atomic number 26 is Iron (Fe)
*(Note: Since electrons = protons, it’s a neutral atom.)*
b. 53 protons, 74 neutrons
→ Protons = 53 → Element with atomic number 53 is Iodine (I)
c. 2 electrons (neutral atoms)
→ Neutral atom means electrons = protons → So protons = 2 → Element is Helium (He)
d. 20 protons
→ Atomic number 20 → Calcium (Ca)
e. 86 electrons, 125 neutrons, 82 protons
→ Protons = 82 → Element is Lead (Pb)
*(Electrons ≠ protons → it’s an ion, but we still identify by protons.)*
f. 0 neutrons
→ Only one element has an isotope with 0 neutrons: Hydrogen-1 (just 1 proton, 0 neutrons) → So element is Hydrogen (H)
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Question 11: If you know ONLY the following information, can you ALWAYS determine what the element is? (Yes/No)
a. Number of protons → YES. Protons define the element. Always.
b. Number of neutrons → NO. Different elements can have same number of neutrons. Also, isotopes of same element have different neutrons.
c. Number of electrons in a neutral atom → YES. In neutral atom, electrons = protons → so you get atomic number → identifies element.
d. Number of electrons → NO. Could be an ion. For example, Na⁺ has 10 electrons, but so does Ne (neutral). You don’t know if it’s neutral or charged → can’t always tell the element.
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Question 12: Fill in the missing items in the table
We’ll go row by row. Remember:
- Z = atomic number = # protons
- A = mass number = protons + neutrons
- In neutral atom: # electrons = # protons
- If electrons ≠ protons → it’s an ion (charge = protons - electrons)
- Isotopic symbol: written as ᴬX (where X is symbol, A is mass number)
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Row a: Symbol = Na
Na is sodium → atomic number Z = 11 → so # protons = 11
Assume neutral unless told otherwise → # electrons = 11
But wait — let’s check if any other info is given? No, only symbol. But in typical worksheets, if no charge is mentioned, assume neutral. However, sometimes they expect you to know common ions. But here, since no charge is indicated, and no electron count given, we must assume neutral for now? Wait — actually, looking at row b, they give electrons = 18 and Z=17 → that’s Cl⁻. So maybe row a is also meant to be neutral? Let’s proceed assuming neutral for row a.
So:
- NAME: Sodium
- SYMBOL: Na
- Z: 11
- A: ? Not given → but we need to pick a common isotope. Most common is Na-23 → so A = 23
- # PROTONS: 11
- # ELECTRONS: 11 (neutral)
- # NEUTRONS: A - Z = 23 - 11 = 12
- ISOTOPIC SYMBOL: ²³Na
But wait — the problem doesn’t specify which isotope. Hmm. Maybe we’re supposed to leave A blank? But the table has columns for A and isotopic symbol. Perhaps for row a, since only symbol is given, we use the most abundant isotope. Yes, standard practice.
Alternatively, maybe the worksheet expects us to realize that without more info, we can’t fill A? But that seems unlikely. Let’s look at other rows.
Actually, looking ahead — row c says “Potassium” — so we can fill from name. Row d has symbol F — fluorine. So probably for row a, we are to assume the most common isotope.
I think it’s safe to use A=23 for Na.
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Row b: Z = 17, # electrons = 18
Z = 17 → protons = 17 → element is Chlorine (Cl)
Electrons = 18 → so charge = 17 - 18 = -1 → it’s Cl⁻
NAME: Chloride ion? Or just Chlorine? The column says "NAME" — probably the element name, even if ion. But sometimes they write "chloride". Let’s see context. In chemistry tables, often they put element name and indicate charge elsewhere. But here, no charge column. Maybe just "Chlorine".
But to be precise, since it’s an ion, perhaps write "Chloride"? I think for this level, they might expect "Chlorine" as the element name.
# PROTONS = 17
# ELECTRONS = 18 (given)
# NEUTRONS = ? Not given → again, need to assume isotope. Most common is Cl-35 or Cl-37. But which? Without info, perhaps we can’t fill? But the table requires it. Maybe we leave it blank? But that seems odd.
Wait — perhaps for rows where neutrons aren’t determined, we can calculate if we had A, but we don’t. This is tricky.
Looking back at question 10, they gave specific neutrons. Here, for row b, only Z and electrons given. So we cannot determine neutrons or A without more info. But the table has those columns. Maybe the worksheet intends for us to use the most abundant isotope?
For chlorine, average atomic mass is ~35.45, so two main isotopes: 35 and 37. Abundance: Cl-35 is about 75%, Cl-37 is 25%. Often in such problems, they use Cl-35.
But to be accurate, perhaps we should note that without neutron count, we can’t fill A and neutrons. But since it’s a worksheet, likely they expect Cl-35.
I’ll assume A=35 for chlorine in row b.
So:
- NAME: Chlorine (or Chloride? I’ll put Chlorine for element name)
- SYMBOL: Cl
- Z: 17
- A: 35 (assumed)
- # PROTONS: 17
- # ELECTRONS: 18
- # NEUTRONS: 35 - 17 = 18
- ISOTOPIC SYMBOL: ³⁵Cl
But wait — if it’s an ion, the isotopic symbol usually doesn’t include charge, just the mass number and element. So ³⁵Cl is fine, implying the atom, but we know it’s ion from electron count. Okay.
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Now, the rest of the table is blurred, but from what I can make out:
Row c: NAME = Potassium → K, Z=19, assume neutral → electrons=19, common isotope K-39 → A=39, neutrons=20, isotopic symbol ³⁹K
Row d: SYMBOL = F → Fluorine, Z=9, neutral → electrons=9, common isotope F-19 → A=19, neutrons=10, isotopic symbol ¹⁹F
Row e: NAME = Iron → Fe, Z=26, and # electrons = 24 → so charge = 26-24=+2 → Fe²⁺. Common isotope Fe-56 → A=56, neutrons=30, isotopic symbol ⁵⁶Fe
Row f: # protons = 53 → Iodine, I, Z=53. Assume neutral? But no electron count given. Probably neutral → electrons=53. Common isotope I-127 → A=127, neutrons=74, isotopic symbol ¹²⁷I
Row g: NAME = Silver → Ag, Z=47. Common isotope Ag-107 or 109? Average is 107.87, so often use 107. Assume neutral → electrons=47. Neutrons=60 if A=107. Isotopic symbol ¹⁰⁷Ag
Row h: Z=36 → Krypton, Kr. Neutral → electrons=36. Common isotope Kr-84 → A=84, neutrons=48, isotopic symbol ⁸⁴Kr
Row i: SYMBOL = W → Tungsten, Z=74. Neutral → electrons=74. Common isotope W-184 → A=184, neutrons=110, isotopic symbol ¹⁸⁴W
Row j: Z=29 → Copper, Cu. Neutral → electrons=29. Common isotope Cu-63 → A=63, neutrons=34, isotopic symbol ⁶³Cu
Row k: # protons = 49 → Indium, In. Neutral → electrons=49. Common isotope In-115 → A=115, neutrons=66, isotopic symbol ¹¹⁵In
Row l: # protons = 79, # electrons = 78 → Gold, Au, charge +1. Common isotope Au-197 → A=197, neutrons=118, isotopic symbol ¹⁹⁷Au
Row m: Z=16, # electrons = 18 → Sulfur, S, charge -2. Common isotope S-32 → A=32, neutrons=16, isotopic symbol ³²S
This covers all visible rows.
Now, to compile answers clearly.
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Final Answer:
10.
a. Iron
b. Iodine
c. Helium
d. Calcium
e. Lead
f. Hydrogen
11.
a. Yes
b. No
c. Yes
d. No
12. Table filled as below:
| NAME | SYMBOL | Z | A | # PROTONS | # ELECTRONS | # NEUTRONS | ISOTOPIC SYMBOL |
|------------|--------|----|-----|-----------|-------------|------------|-----------------|
| a. Sodium | Na | 11 | 23 | 11 | 11 | 12 | ²³Na |
| b. Chlorine| Cl | 17 | 35 | 17 | 18 | 18 | ³⁵Cl |
| c. Potassium| K | 19 | 39 | 19 | 19 | 20 | ³⁹K |
| d. Fluorine| F | 9 | 19 | 9 | 9 | 10 | ¹⁹F |
| e. Iron | Fe | 26 | 56 | 26 | 24 | 30 | ⁵⁶Fe |
| f. Iodine | I | 53 | 127 | 53 | 53 | 74 | ¹²⁷I |
| g. Silver | Ag | 47 | 107 | 47 | 47 | 60 | ¹⁰⁷Ag |
| h. Krypton | Kr | 36 | 84 | 36 | 36 | 48 | ⁸⁴Kr |
| i. Tungsten| W | 74 | 184 | 74 | 74 | 110 | ¹⁸⁴W |
| j. Copper | Cu | 29 | 63 | 29 | 29 | 34 | ⁶³Cu |
| k. Indium | In | 49 | 115 | 49 | 49 | 66 | ¹¹⁵In |
| l. Gold | Au | 79 | 197 | 79 | 78 | 118 | ¹⁹⁷Au |
| m. Sulfur | S | 16 | 32 | 16 | 18 | 16 | ³²S |
*Note: For isotopes, the most abundant or commonly used isotope was assumed where not specified.*
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Question 10: Name the element which has the following numbers of particles
Remember: The number of protons tells you what element it is. That’s the atomic number (Z). Electrons can change if it’s an ion, but protons define the element. Neutrons help find the mass number (A = protons + neutrons), but not the identity.
a. 26 electrons, 29 neutrons, 26 protons
→ Protons = 26 → Element with atomic number 26 is Iron (Fe)
*(Note: Since electrons = protons, it’s a neutral atom.)*
b. 53 protons, 74 neutrons
→ Protons = 53 → Element with atomic number 53 is Iodine (I)
c. 2 electrons (neutral atoms)
→ Neutral atom means electrons = protons → So protons = 2 → Element is Helium (He)
d. 20 protons
→ Atomic number 20 → Calcium (Ca)
e. 86 electrons, 125 neutrons, 82 protons
→ Protons = 82 → Element is Lead (Pb)
*(Electrons ≠ protons → it’s an ion, but we still identify by protons.)*
f. 0 neutrons
→ Only one element has an isotope with 0 neutrons: Hydrogen-1 (just 1 proton, 0 neutrons) → So element is Hydrogen (H)
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Question 11: If you know ONLY the following information, can you ALWAYS determine what the element is? (Yes/No)
a. Number of protons → YES. Protons define the element. Always.
b. Number of neutrons → NO. Different elements can have same number of neutrons. Also, isotopes of same element have different neutrons.
c. Number of electrons in a neutral atom → YES. In neutral atom, electrons = protons → so you get atomic number → identifies element.
d. Number of electrons → NO. Could be an ion. For example, Na⁺ has 10 electrons, but so does Ne (neutral). You don’t know if it’s neutral or charged → can’t always tell the element.
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Question 12: Fill in the missing items in the table
We’ll go row by row. Remember:
- Z = atomic number = # protons
- A = mass number = protons + neutrons
- In neutral atom: # electrons = # protons
- If electrons ≠ protons → it’s an ion (charge = protons - electrons)
- Isotopic symbol: written as ᴬX (where X is symbol, A is mass number)
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Row a: Symbol = Na
Na is sodium → atomic number Z = 11 → so # protons = 11
Assume neutral unless told otherwise → # electrons = 11
But wait — let’s check if any other info is given? No, only symbol. But in typical worksheets, if no charge is mentioned, assume neutral. However, sometimes they expect you to know common ions. But here, since no charge is indicated, and no electron count given, we must assume neutral for now? Wait — actually, looking at row b, they give electrons = 18 and Z=17 → that’s Cl⁻. So maybe row a is also meant to be neutral? Let’s proceed assuming neutral for row a.
So:
- NAME: Sodium
- SYMBOL: Na
- Z: 11
- A: ? Not given → but we need to pick a common isotope. Most common is Na-23 → so A = 23
- # PROTONS: 11
- # ELECTRONS: 11 (neutral)
- # NEUTRONS: A - Z = 23 - 11 = 12
- ISOTOPIC SYMBOL: ²³Na
But wait — the problem doesn’t specify which isotope. Hmm. Maybe we’re supposed to leave A blank? But the table has columns for A and isotopic symbol. Perhaps for row a, since only symbol is given, we use the most abundant isotope. Yes, standard practice.
Alternatively, maybe the worksheet expects us to realize that without more info, we can’t fill A? But that seems unlikely. Let’s look at other rows.
Actually, looking ahead — row c says “Potassium” — so we can fill from name. Row d has symbol F — fluorine. So probably for row a, we are to assume the most common isotope.
I think it’s safe to use A=23 for Na.
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Row b: Z = 17, # electrons = 18
Z = 17 → protons = 17 → element is Chlorine (Cl)
Electrons = 18 → so charge = 17 - 18 = -1 → it’s Cl⁻
NAME: Chloride ion? Or just Chlorine? The column says "NAME" — probably the element name, even if ion. But sometimes they write "chloride". Let’s see context. In chemistry tables, often they put element name and indicate charge elsewhere. But here, no charge column. Maybe just "Chlorine".
But to be precise, since it’s an ion, perhaps write "Chloride"? I think for this level, they might expect "Chlorine" as the element name.
# PROTONS = 17
# ELECTRONS = 18 (given)
# NEUTRONS = ? Not given → again, need to assume isotope. Most common is Cl-35 or Cl-37. But which? Without info, perhaps we can’t fill? But the table requires it. Maybe we leave it blank? But that seems odd.
Wait — perhaps for rows where neutrons aren’t determined, we can calculate if we had A, but we don’t. This is tricky.
Looking back at question 10, they gave specific neutrons. Here, for row b, only Z and electrons given. So we cannot determine neutrons or A without more info. But the table has those columns. Maybe the worksheet intends for us to use the most abundant isotope?
For chlorine, average atomic mass is ~35.45, so two main isotopes: 35 and 37. Abundance: Cl-35 is about 75%, Cl-37 is 25%. Often in such problems, they use Cl-35.
But to be accurate, perhaps we should note that without neutron count, we can’t fill A and neutrons. But since it’s a worksheet, likely they expect Cl-35.
I’ll assume A=35 for chlorine in row b.
So:
- NAME: Chlorine (or Chloride? I’ll put Chlorine for element name)
- SYMBOL: Cl
- Z: 17
- A: 35 (assumed)
- # PROTONS: 17
- # ELECTRONS: 18
- # NEUTRONS: 35 - 17 = 18
- ISOTOPIC SYMBOL: ³⁵Cl
But wait — if it’s an ion, the isotopic symbol usually doesn’t include charge, just the mass number and element. So ³⁵Cl is fine, implying the atom, but we know it’s ion from electron count. Okay.
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Now, the rest of the table is blurred, but from what I can make out:
Row c: NAME = Potassium → K, Z=19, assume neutral → electrons=19, common isotope K-39 → A=39, neutrons=20, isotopic symbol ³⁹K
Row d: SYMBOL = F → Fluorine, Z=9, neutral → electrons=9, common isotope F-19 → A=19, neutrons=10, isotopic symbol ¹⁹F
Row e: NAME = Iron → Fe, Z=26, and # electrons = 24 → so charge = 26-24=+2 → Fe²⁺. Common isotope Fe-56 → A=56, neutrons=30, isotopic symbol ⁵⁶Fe
Row f: # protons = 53 → Iodine, I, Z=53. Assume neutral? But no electron count given. Probably neutral → electrons=53. Common isotope I-127 → A=127, neutrons=74, isotopic symbol ¹²⁷I
Row g: NAME = Silver → Ag, Z=47. Common isotope Ag-107 or 109? Average is 107.87, so often use 107. Assume neutral → electrons=47. Neutrons=60 if A=107. Isotopic symbol ¹⁰⁷Ag
Row h: Z=36 → Krypton, Kr. Neutral → electrons=36. Common isotope Kr-84 → A=84, neutrons=48, isotopic symbol ⁸⁴Kr
Row i: SYMBOL = W → Tungsten, Z=74. Neutral → electrons=74. Common isotope W-184 → A=184, neutrons=110, isotopic symbol ¹⁸⁴W
Row j: Z=29 → Copper, Cu. Neutral → electrons=29. Common isotope Cu-63 → A=63, neutrons=34, isotopic symbol ⁶³Cu
Row k: # protons = 49 → Indium, In. Neutral → electrons=49. Common isotope In-115 → A=115, neutrons=66, isotopic symbol ¹¹⁵In
Row l: # protons = 79, # electrons = 78 → Gold, Au, charge +1. Common isotope Au-197 → A=197, neutrons=118, isotopic symbol ¹⁹⁷Au
Row m: Z=16, # electrons = 18 → Sulfur, S, charge -2. Common isotope S-32 → A=32, neutrons=16, isotopic symbol ³²S
This covers all visible rows.
Now, to compile answers clearly.
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Final Answer:
10.
a. Iron
b. Iodine
c. Helium
d. Calcium
e. Lead
f. Hydrogen
11.
a. Yes
b. No
c. Yes
d. No
12. Table filled as below:
| NAME | SYMBOL | Z | A | # PROTONS | # ELECTRONS | # NEUTRONS | ISOTOPIC SYMBOL |
|------------|--------|----|-----|-----------|-------------|------------|-----------------|
| a. Sodium | Na | 11 | 23 | 11 | 11 | 12 | ²³Na |
| b. Chlorine| Cl | 17 | 35 | 17 | 18 | 18 | ³⁵Cl |
| c. Potassium| K | 19 | 39 | 19 | 19 | 20 | ³⁹K |
| d. Fluorine| F | 9 | 19 | 9 | 9 | 10 | ¹⁹F |
| e. Iron | Fe | 26 | 56 | 26 | 24 | 30 | ⁵⁶Fe |
| f. Iodine | I | 53 | 127 | 53 | 53 | 74 | ¹²⁷I |
| g. Silver | Ag | 47 | 107 | 47 | 47 | 60 | ¹⁰⁷Ag |
| h. Krypton | Kr | 36 | 84 | 36 | 36 | 48 | ⁸⁴Kr |
| i. Tungsten| W | 74 | 184 | 74 | 74 | 110 | ¹⁸⁴W |
| j. Copper | Cu | 29 | 63 | 29 | 29 | 34 | ⁶³Cu |
| k. Indium | In | 49 | 115 | 49 | 49 | 66 | ¹¹⁵In |
| l. Gold | Au | 79 | 197 | 79 | 78 | 118 | ¹⁹⁷Au |
| m. Sulfur | S | 16 | 32 | 16 | 18 | 16 | ³²S |
*Note: For isotopes, the most abundant or commonly used isotope was assumed where not specified.*
Parent Tip: Review the logic above to help your child master the concept of basic atomic structure worksheet.
