Here are the answers to your worksheet.
1. Using the symbol box for Sulfur (S)
To solve this, we look at the numbers in the box:
*
Top number (32): This is the Mass Number.
*
Bottom number (16): This is the Atomic Number.
*
Atomic Number tells us the number of
Protons.
* In a neutral atom, the number of
Electrons equals the number of Protons.
* To find
Neutrons, subtract the bottom number from the top number ($32 - 16$).
Answers:
a. What is the atomic number?
16
b. What is the mass number?
32
c. How many electrons?
16
d. How many neutrons?
16
e. How many protons?
16
***
2. Fill in the missing information
For these problems, remember:
* The
bottom number (subscript) is the number of
protons. It also identifies the element on the periodic table.
* The
top number (superscript) is the
mass number.
*
Neutrons = Top Number $-$ Bottom Number.
Row 1:
*
${}_{2}^{4}\text{He}$: Element is Helium. Protons: 2. Neutrons: $4 - 2 = 2$.
*
${}_{26}^{56}\text{Fe}$: Element is Iron. Protons: 26. Neutrons: $56 - 26 = 30$.
*
${}_{13}^{27}\text{Al}$: Element is Aluminum. Protons: 13. Neutrons: $27 - 13 = 14$.
Row 2:
*
${}_{20}^{40}\text{Ca}$: Element is Calcium. Protons: 20. Neutrons: $40 - 20 = 20$.
*
${}_{26}^{56}\text{Ne}$: *Note: The symbol says Ne (Neon), but the number 26 belongs to Iron (Fe). Based on the atomic number 26 provided:* Element is Iron. Protons: 26. Neutrons: $56 - 26 = 30$.
*
${}_{6}^{12}\text{C}$: Element is Carbon. Protons: 6. Neutrons: $12 - 6 = 6$.
Row 3:
*
${}_{9}^{19}\text{F}$: Element is Fluorine. Protons: 9. Neutrons: $19 - 9 = 10$.
*
${}_{17}^{35}\text{Cl}$: Element is Chlorine. Protons: 17. Neutrons: $35 - 17 = 18$.
*
${}_{11}^{23}\text{Na}$: Element is Sodium. Protons: 11. Neutrons: $23 - 11 = 12$.
Row 4:
*
${}_{56}^{130}\text{Ba}$: Element is Barium. Protons: 56. Neutrons: $130 - 56 = 74$.
*
${}_{26}^{56}\text{Fe}$: Element is Iron. Protons: 26. Neutrons: $56 - 26 = 30$.
*
${}_{35}^{79}\text{Br}$: Element is Bromine. Protons: 35. Neutrons: $79 - 35 = 44$.
Final Answer:
1. Sulfur Questions:
a. 16
b. 32
c. 16
d. 16
e. 16
2. Atom Symbols Table:
| Symbol | Element Name | # of Protons | # of Neutrons |
| :--- | :--- | :--- | :--- |
| ${}_{2}^{4}\text{He}$ | Helium | 2 | 2 |
| ${}_{26}^{56}\text{Fe}$ | Iron | 26 | 30 |
| ${}_{13}^{27}\text{Al}$ | Aluminum | 13 | 14 |
| ${}_{20}^{40}\text{Ca}$ | Calcium | 20 | 20 |
| ${}_{26}^{56}\text{Ne}$* | Iron** | 26 | 30 |
| ${}_{6}^{12}\text{C}$ | Carbon | 6 | 6 |
| ${}_{9}^{19}\text{F}$ | Fluorine | 9 | 10 |
| ${}_{17}^{35}\text{Cl}$ | Chlorine | 17 | 18 |
| ${}_{11}^{23}\text{Na}$ | Sodium | 11 | 12 |
| ${}_{56}^{130}\text{Ba}$ | Barium | 56 | 74 |
| ${}_{26}^{56}\text{Fe}$ | Iron | 26 | 30 |
| ${}_{35}^{79}\text{Br}$ | Bromine | 35 | 44 |
*\*Note on ${}_{26}^{56}\text{Ne}$: The worksheet lists the symbol for Neon (Ne) but gives it the atomic number for Iron (26). The answers above are calculated based on the number 26 provided in the problem.*
Parent Tip: Review the logic above to help your child master the concept of protons neutrons and electrons practice worksheet.
