Create List and Rank-Order chemPad Questions

When you create chemPad questions that are answered with a list of items, you can choose whether order is important or not.

Unordered lists are delimited by commas and order is not important, so the following responses are equivalent:
  • Li, Na, K
  • K, Na, Li
Rank-order lists are delimited by three symbols: >, <, and =. These symbols are used to indicate items' relative ranking, so the following responses are not equivalent:
  • H < He < Li
  • Li < H < He
Either-order lists, like rank-order lists, are delimited by three symbols: >, <, and =. These symbols are used to indicate items' relative ranking, but your students can specify their response either in ascending or descending order, so the following responses are equivalent:
  • H < He < Li
  • Li > He > H
Note:  Do not specify answer keys containing the < or > characters directly in Answer, as these characters might be interpreted as the start or end of a tag. Instead, assign your answer key to a variable and reference the variable as described in this topic.

To create a chemPad question for which the answer is a list:

  1. Click Questions > Create. The Question Editor opens.
  2. In Name, type a name for the question.
  3. In Mode, select Fill-in-the-Blank.
  4. In Question, add the following code, replacing answer_key with your answer key:
    <eqn>
    $mykey='answer_key';
    ''
    </eqn>

    This code assigns your answer key to the variable $mykey. You can use a different variable name if needed.

    For example:

    Answer

    Code

    He, Ne, Ar, Kr, Xe, Rn (in any order)

    <eqn>
    $mykey='He, Ne, Ar, Kr, Xe, Rn';
    ''
    </eqn>

    NO2 > N2 > NH3  

    <eqn>
    $mykey='NO_{2} > N_{2} > NH_{3}';
    ''
    </eqn>

    NO2 > N2 > NH3   or NH3 < N2 < NO2  

    <eqn>
    $mykey='NO_{2} > N_{2} > NH_{3}';
    ''
    </eqn>
    Note: To ensure that your answer key is unambiguous, always specify rank-order answer keys in either ascending or descending order.

    Incorrect: Li > H < He

    Correct: H < He < Li

    Correct: Li > He > H

  5. In Question, type your question.
    Provide relevant information about assumptions or expectations for the question, for example, the conditions for the question — STP, SATP, or reaction/prevailing conditions — or whether states-of-matter should be specified in the response. Use the answer placeholder string <_> to specify where the answer box should be displayed.
  6. In Answer, type the following items on a single line: 
    <EQN $PAD='chem'; $CHEM='method'; $mykey>

    where method is one of the following chemPad parsing methods:   

    List Type

    Delimiters

    Method

    Unordered

    ,

    rnk

    Rank-order

    ><=

    rnk

    Either-order

    ><=

    rnk,either

    For example:  

    Answer

    Code

    He, Ne, Ar, Kr, Xe, Rn (in any order)

    <EQN $PAD='chem'; $CHEM='rnk'; $mykey>

    NO2 > N2 > NH3  

    <EQN $PAD='chem'; $CHEM='rnk'; $mykey>

    NO2 > N2 > NH3   or NH3 < N2 < NO2  

    <EQN $PAD='chem'; $CHEM='rnk,either'; $mykey>

    By default, your students must specify each chemical formula exactly as listed in your answer key. To allow specific kinds of notation, you can add a comma and one of the following methods after rnk or rnk,either:  

    Notation

    Example

    Method

    Formula elements in any order

    CH4N2O or CN2H4O

    fmla

    Condensed formulas

    (NH2)2CO or CH4N2O

    fmla,index

    Solvate dot

    CuSO4 · 6 H2O

    solvate

    Nuclear particles and nuclides

    0-1 β or 0-1 e

    nclr

    Nuclear particles with charges

    42 He 2+
    nclr,ion

    Ion charges

    Mg2+ or Mg+2 

    ion

    Ionizable protons first

    CH3CO2H or HCH3CO2 

    ion,acid

    For example:

    <EQN $PAD='chem'; $CHEM='rnk,either,fmla,index'; $mykey>   
    Note:
    • Specify methods only in the order listed here.
    • If an answer extends beyond the right side of the Answer box, it is wrapped to the next line, but it is still considered a single line so long as you do not press ENTER.
    • As with other fill-in-the-blank questions, you can specify alternative answer keys separated by the characters {tab}. For example:
      <EQN $PAD='chem'; $CHEM='rnk'; $mykey> {tab} <EQN $mykey2>
    • For information about how to specify chemical notation in your answer key, see Creating chemPad Answer Keys.
  7. Optional: Type a Solution.

    The solution helps your students understand the steps they need to take to determine the correct answer to the question. Your assignment settings specify when to show the solution.

  8. Click Test/Preview to test the appearance and behavior of the question. See Test Questions.
  9. Click Redisplay to show certain kinds of errors in the Display section of the Question Editor. Make any needed changes to your question.
  10. Optional: Click Show Additional Information and change the question's sharing permission or add descriptive information.
    • By default, other instructors can use your question only if you provide them with the question ID, and only you can edit the question or find it in search results. To change the permission, see Share Questions With Other Instructors.
    • If you make your question publicly available, you might want to provide descriptive information to help others search for it. See Add Search Metadata to Questions.
  11. When your question displays and functions correctly, click Save.

    WebAssign assigns it a unique question ID (QID), which is displayed in parentheses after the question name.

    You can use your question in an assignment and see it in your My Questions list only after it is saved.

Example chemPad Question (Unordered List)

The following table summarizes an actual question.

QID

1534331

Name

Template2 5.CHEMP.04.

Mode

Fill-in-the-Blank

Question

<eqn>
$mykey='He, Ne, Ar, Kr, Xe, Rn';
''
</eqn>
List the noble gases in any order. (Separate substances in the list 
with a comma.)<br>
<_>

Answer

<EQN $PAD='chem'; $CHEM='rnk'; $mykey>

Display to Students

Question as displayed to students

Example chemPad Question (Rank-Order List)

The following table summarizes an actual question.

QID

1534321

Name

Template2 5.CHEMP.05.

Mode

Fill-in-the-Blank

Question

<eqn>
$mykey='NO_{2} > N_{2} > NH_{3}';
''
</eqn>
Rank the following gases by mass density (at identical temperatures 
and pressures) in decreasing order: <h:chemical>N_2, NH_3, and 
NO_2</h:chemical>. (Use the appropriate <, =, or > symbol to 
separate substances in the list.)<br>
<_>

Answer

<EQN $PAD='chem'; $CHEM='rnk'; $mykey>

Display to Students

Question as displayed to students

Example chemPad Question (Either-Order List)

The following table summarizes an actual question.

QID

1534315

Name

Template2 5.CHEMP.06.

Mode

Fill-in-the-Blank

Question

<eqn>
$mykey='NO_{2} > N_{2} > NH_{3}';
''
</eqn>
Rank the following gases by mass density (at identical temperatures 
and pressures): <h:chemical>N_2, NH_3, and NO_2</h:chemical>. 
(Use the appropriate <, =, or > symbol to separate substances 
in the list.)<br>
<_>

Answer

<EQN $PAD='chem'; $CHEM='rnk,either'; $mykey>

Display to Students

Question as displayed to students