The periodic table
4 marks · NormalThe table shows data for four elements.
| Element | Symbol | Atomic number | Mass number |
|---|---|---|---|
| Sulfur | S | 16 | 32 |
| Iron | Fe | 26 | 56 |
| Nickel | Ni | 28 | 59 |
| Krypton | Kr | 36 | 84 |
Use the information to complete the table below by filling in the number of neutrons for each element.
| Element | Number of neutrons |
|---|---|
| Sulfur | |
| Iron | |
| Nickel | |
| Krypton |
Which element in the table has the greatest number of protons?
Which element in the table has the same number of protons as electrons?
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) Sulfur: 16; Iron: 30; Nickel: 31; Krypton: 48
(b) Krypton
(c) All (Sulfur, Iron, Nickel, Krypton)
Show mark scheme and worked solution
Marking points
M1 (a) · 1 mark · Correctly calculates neutrons for any three elements.
A1 (a) · 1 mark · All four numbers of neutrons correct.
B1 (b) · 1 mark · Correctly identifies krypton as having the greatest number of protons.
B2 (c) · 1 mark · Identifies that all listed elements have the same number of protons as electrons (for neutral atoms).
Worked solution
| Element | Number of neutrons |
|---|---|
| Sulfur | 32 - 16 = 16 |
| Iron | 56 - 26 = 30 |
| Nickel | 59 - 28 = 31 |
| Krypton | 84 - 36 = 48 |
(b) Krypton has the greatest number of protons (36).
(c) All the elements listed have the same number of protons and electrons, as they are neutral atoms.