Sigma Learn

1aEasy1 mark

Atomic Particles, Atomic Radius and Isotopes: which definition in the notes describes Proton?

2aEasy1 mark

Atomic Particles, Atomic Radius and Isotopes: which definition in the notes describes Neutron?

3aEasy1 mark

Type the exact authored definition of Electron. This is the language needed before analysing this chemistry case: Two isotopes of X have masses 63.0 and 65.0. Explain how their abundances determine the relative atomic mass of X, and state a check on your calculated value.

Exact chemistry response

4aEasy1 mark

Sort each statement as an accurate lesson statement or a mismatched definition. Keep the source case in view: Two isotopes of X have masses 63.0 and 65.0. Explain how their abundances determine the relative atomic mass of X, and state a check on your calculated value.

Accurate lesson statement

Mismatched definition

5aEasy1 mark

Which authored equation, model, or representation should be placed beside the source case before you evaluate it? Two isotopes of X have masses 63.0 and 65.0. Explain how their abundances determine the relative atomic mass of X, and state a check on your calculated value.

6aEasy3 marks

Use the definition of Proton to write one chemically precise sentence identifying what must be noticed in this source case: Two isotopes of X have masses 63.0 and 65.0. Explain how their abundances determine the relative atomic mass of X, and state a check on your calculated value.

Chemical reasoning

0 / 180 words

7aEasy1 mark

Evaluate these claims before solving the source case. Sort them by whether they preserve the lesson's chemistry. Source case: Two isotopes of X have masses 63.0 and 65.0. Explain how their abundances determine the relative atomic mass of X, and state a check on your calculated value.

Supports the chemistry

Does not support the chemistry

8aEasy5 marks

Construct a short evidence trail for this exact source case: Two isotopes of X have masses 63.0 and 65.0. Explain how their abundances determine the relative atomic mass of X, and state a check on your calculated value.

1.
AIdentify the stated species, data, apparatus, conditions, or observation in the source case
2.
BSelect the relevant definition, beginning with Proton
3.
CWrite or sketch the authored representation: $A_{r} = \frac{\sum ( isotopic mass \times relative abundance )}{\sum ( relative abundance )}$
4.
DApply the representation to the stated chemical evidence
5.
ECheck that the conclusion still agrees with Electron

9aEasy3 marks

For the source case, state the first chemical representation or calculation you would construct and explain why it is more useful than merely naming Neutron. Source case: Two isotopes of X have masses 63.0 and 65.0. Explain how their abundances determine the relative atomic mass of X, and state a check on your calculated value.

Chemical reasoning

0 / 180 words

10aEasy5 marks

Use the canvas for a labelled chemical diagram, equation layout, particle model, energy profile, apparatus sketch, spectrum annotation, reaction mechanism, table, or flowchart where it clarifies your answer.

Construct a simple labelled model for the source case: Two isotopes of X have masses 63.0 and 65.0. Explain how their abundances determine the relative atomic mass of X, and state a check on your calculated value. Include one label using Proton, one label using Electron, and the key representation

A_{r} = \frac{\sum ( isotopic mass \times relative abundance )}{\sum ( relative abundance )}

.

Draw with the mouse or a finger.

11aMedium5 marks

Evaluate the authored source case with a complete chemical argument, calculation, equation, diagram description, or data interpretation as appropriate: Two isotopes of X have masses 63.0 and 65.0. Explain how their abundances determine the relative atomic mass of X, and state a check on your calculated value.

Chemical reasoning

0 / 180 words

12aMedium1 mark

Which response would make a solution to the source case chemically defensible? Two isotopes of X have masses 63.0 and 65.0. Explain how their abundances determine the relative atomic mass of X, and state a check on your calculated value.

13aMedium1 mark

Sort the candidate statements about the source case into conclusions supported by the chemistry and statements needing correction. Source case: Two isotopes of X have masses 63.0 and 65.0. Explain how their abundances determine the relative atomic mass of X, and state a check on your calculated value.

Supported by the chemistry

Needs correction

14aMedium6 marks

Put a full solution path for the source case in order. Source case: Two isotopes of X have masses 63.0 and 65.0. Explain how their abundances determine the relative atomic mass of X, and state a check on your calculated value.

1.
AExtract the relevant species, measurements, conditions, observations, or structural evidence
2.
BState the chemically relevant definition, such as Proton
3.
CSet up $A_{r} = \frac{\sum ( isotopic mass \times relative abundance )}{\sum ( relative abundance )}$
4.
DCarry out the required calculation, equation balancing, mechanism, interpretation, or particle-level explanation
5.
EState the specific conclusion for this case
6.
FValidate the conclusion against Electron and the stated case conditions

15aMedium4 marks

The source-case answer is: Use mass × abundance for each isotope, add the contributions, and check that the answer is between 63.0 and 65.0. Explain which two pieces of evidence or reasoning make that answer defensible, using Proton and

A_{r} = \frac{\sum ( isotopic mass \times relative abundance )}{\sum ( relative abundance )}

.

Chemical reasoning

0 / 180 words

16aMedium5 marks

Evaluate this source case: Two isotopes of X have masses 63.0 and 65.0. Explain how their abundances determine the relative atomic mass of X, and state a check on your calculated value. Check every use of

A_{r} = \frac{\sum ( isotopic mass \times relative abundance )}{\sum ( relative abundance )}

and the definition of Electron. Write a chemical conclusion and name one precise check that could expose an error.

Chemical reasoning

0 / 180 words

17aMedium4 marks

A student begins the source case by writing “Proton means An uncharged particle in the nucleus with relative mass 1.” and then tries to apply

A_{r} = \frac{\sum ( isotopic mass \times relative abundance )}{\sum ( relative abundance )}

. Diagnose the chemical error and repair the first two reasoning steps for this case: Two isotopes of X have masses 63.0 and 65.0. Explain how their abundances determine the relative atomic mass of X, and state a check on your calculated value.

Chemical reasoning

0 / 180 words

18aMedium1 mark

After evaluating the source case, which final check is most relevant to this lesson? Two isotopes of X have masses 63.0 and 65.0. Explain how their abundances determine the relative atomic mass of X, and state a check on your calculated value.

19aMedium5 marks

Use the canvas for a labelled chemical diagram, equation layout, particle model, energy profile, apparatus sketch, spectrum annotation, reaction mechanism, table, or flowchart where it clarifies your answer.

Construct an annotated representation that makes the chain from evidence to conclusion visible for the source case: Two isotopes of X have masses 63.0 and 65.0. Explain how their abundances determine the relative atomic mass of X, and state a check on your calculated value. Use

A_{r} = \frac{\sum ( isotopic mass \times relative abundance )}{\sum ( relative abundance )}

, and label where Neutron or Isotope helps you interpret the case.

Draw with the mouse or a finger.

20aMedium5 marks

Compare a guided explanation of the source case with an independent solution. Use the actual case (Two isotopes of X have masses 63.0 and 65.0. Explain how their abundances determine the relative atomic mass of X, and state a check on your calculated value.) to state what evidence must be supplied in both versions, and explain how Relative atomic mass,

A_{r}

would prevent a careless conclusion.

Chemical reasoning

0 / 180 words

21aHard6 marks

Alter exactly one stated species, value, condition, observation, structural feature, or procedural choice in the source case, then evaluate whether the original conclusion still follows. Make the changed case explicit and use

A_{r} = \frac{\sum ( isotopic mass \times relative abundance )}{\sum ( relative abundance )}

. Original case: Two isotopes of X have masses 63.0 and 65.0. Explain how their abundances determine the relative atomic mass of X, and state a check on your calculated value.

Chemical reasoning

0 / 180 words

22aHard1 mark

Act as a chemistry examiner. Sort these candidate uses of the source case by the standard of evidence they provide. Source case: Two isotopes of X have masses 63.0 and 65.0. Explain how their abundances determine the relative atomic mass of X, and state a check on your calculated value.

Defensible chemical reasoning

Insufficient or incorrect reasoning

23aHard6 marks

create one fully specified close analogue of the source case, changing a real chemical detail while keeping the same lesson principle. Solve or evaluate your new case with

A_{r} = \frac{\sum ( isotopic mass \times relative abundance )}{\sum ( relative abundance )}

, then compare its conclusion with the source answer. Source case: Two isotopes of X have masses 63.0 and 65.0. Explain how their abundances determine the relative atomic mass of X, and state a check on your calculated value.

Chemical reasoning

0 / 180 words

24aHard5 marks

Use the canvas for a labelled chemical diagram, equation layout, particle model, energy profile, apparatus sketch, spectrum annotation, reaction mechanism, table, or flowchart where it clarifies your answer.

Source case: Two isotopes of X have masses 63.0 and 65.0. Explain how their abundances determine the relative atomic mass of X, and state a check on your calculated value.

Draw with the mouse or a finger.

25aHard1 mark

Which examiner comment best improves a weak answer to this source case? Two isotopes of X have masses 63.0 and 65.0. Explain how their abundances determine the relative atomic mass of X, and state a check on your calculated value.

26aHard6 marks

Construct a rigorous quality-assurance sequence for a high-mark response to the source case: Two isotopes of X have masses 63.0 and 65.0. Explain how their abundances determine the relative atomic mass of X, and state a check on your calculated value.

1.
ASpecify exactly which species, data, apparatus detail, condition, observation, or structural feature the case supplies
2.
BSelect and define the relevant chemistry, including Proton and Electron
3.
CSet up the appropriate equation, model, mechanism, diagram, spectrum interpretation, or calculation: $A_{r} = \frac{\sum ( isotopic mass \times relative abundance )}{\sum ( relative abundance )}$
4.
DDerive the case-specific result with visible chemical reasoning
5.
ETest the result against charges, atoms, units, signs, conditions, observations, or theoretical assumptions as appropriate
6.
FCommunicate the conclusion with a chemical justification tied to the source case

27aHard6 marks

Use both Proton and Atomic radius to construct a two-link explanation of the source case. Your answer must show how each idea constrains the interpretation, rather than listing two definitions. Source case: Two isotopes of X have masses 63.0 and 65.0. Explain how their abundances determine the relative atomic mass of X, and state a check on your calculated value.

Chemical reasoning

0 / 180 words

28aHard5 marks

Turn the source case into a testable chemistry check. Specify one measurement, observation, apparatus choice, control, data feature, structural label, or safety precaution that would make the interpretation more reliable, and explain its connection to

A_{r} = \frac{\sum ( isotopic mass \times relative abundance )}{\sum ( relative abundance )}

. Source case: Two isotopes of X have masses 63.0 and 65.0. Explain how their abundances determine the relative atomic mass of X, and state a check on your calculated value.

Chemical reasoning

0 / 180 words

29aHard1 mark

Audit four candidate final answers to the source case. Sort each by whether it would earn substantial chemistry credit. Source case: Two isotopes of X have masses 63.0 and 65.0. Explain how their abundances determine the relative atomic mass of X, and state a check on your calculated value.

Substantial chemistry credit

Limited or no chemistry credit

30aHard7 marks

construct and solve a four-stage chemistry problem rooted in this source case: Two isotopes of X have masses 63.0 and 65.0. Explain how their abundances determine the relative atomic mass of X, and state a check on your calculated value. Include a new but stated chemical condition, use

A_{r} = \frac{\sum ( isotopic mass \times relative abundance )}{\sum ( relative abundance )}

, make Proton and Atomic radius necessary to the reasoning, and end with a check on the conclusion.

Chemical reasoning

0 / 180 words

Atomic Particles, Atomic Radius and Isotopes Assessment

Questions