Begin with two source-supported records, then compare their group and period. Label the exercise as a selected subset so it does not pretend to be the whole periodic table.
Two labeled element records
Original practice layout using selected reference facts:
| Field | Carbon | Oxygen |
|---|---|---|
| Symbol | C | O |
| Atomic number | 6 | 8 |
| Relative atomic mass | 12.011 | 15.999 |
| Group | 14 | 16 |
| Period | 2 | 2 |
The values are from the Royal Society of Chemistry's carbon and oxygen records. Atomic number gives proton count. Relative atomic mass is a different field; its decimal value is not the proton count or a specified isotope's mass number.
Ask for the field and the answer
For Carbon, ask “Which field tells you the number of protons?” Offer Atomic number, Relative atomic mass, Group, and Period. Then ask “What is that count?” The answer is 6, with the field label still visible.
If the learner chooses 12.011, feedback should say that they selected relative atomic mass and redirect them to the atomic-number label. Rounding it to 12 does not resolve the field error. For Oxygen, the corresponding proton count is 8.
Keep the question narrow. Subtracting 6 from the averaged mass 12.011 does not supply an exact neutron count for an unspecified carbon isotope. A neutron-count extension needs an explicitly named isotope and its mass number; those inputs are outside this two-record task.
Compare position without closing the gaps
A group is a vertical column; a period is a horizontal row. Carbon and Oxygen are both in period 2 but belong to different groups, 14 and 16. Ask “What do these two records share?” and “Which position field differs?”
If the reading copy uses a structural diagram, put C under group 14 and O under group 16, leaving group 15 visibly unfilled in the selected subset. Label other positions omitted. Do not draw C and O as consecutive complete-table neighbors; the subset leaves other elements out.
For local practice, selecting an element should update both its field values and the matching key. Selecting a new question should clear the old answer. An unanswered item stays unanswered; feedback explains the field role rather than producing a general chemistry score.
Copy a fact-labeled worksheet prompt
Create an original periodic-table field-reading worksheet in US English.
Learner context: [enter or TO CONFIRM]
Primary-source element records and URLs: [paste]
Fields to practice: [atomic number/proton count, relative mass, group, period]
Selected subset and omitted positions: [enter]
Keep every number beside its field name. Ask for the relevant field and then
the value; explain incorrect field choices. Distinguish atomic number from
relative atomic mass and group from period. Do not calculate exact neutrons
from averaged mass or invent unspecified isotope data. Preserve source values.
If a structural diagram is used, retain actual group/period positions and
show gaps/omissions. Do not claim a complete table from a selected subset.
Return original prompts, keys, feedback and full text descriptions. If
requested, make HTML local practice with keyboard element/question choices
and reset. Element changes update facts/key and clear stale answers. No
response collection, chemical experiments, or automatic proficiency score.
Read each tile aloud with a teacher: field name first, value second. An HTML practice copy can be saved and displayed in NOS while you verify those labels and the period/group comparison. Keep learners focused on why 6 answers Carbon's proton question rather than on memorizing whichever number is most visually prominent.