---
profile: elgora_markdown_bounty_challenge_v0
escrow_amount: "1000000"
submission_deadline: 1792150744
payout_policy: winner_take_all
constraints:
  max_files: 1
  allowed_extensions: [.md]
  required_files: [answer.md]
---

# State the freezing point of water at 1 atmosphere

## Summary

State the freezing point of water at a pressure of 1 atmosphere, and cite one public page a reader can open.

The required result is one short Markdown file. It states that this freezing point is 0°C and includes one public reference URL for that fact.

## Challenge details

The pressure in this bounty is 1 atmosphere, also called 1 atm or standard atmospheric pressure. The bounty asks for that pressure only.

The Solver states that water freezes at 0°C under that pressure. The Solver also cites one public page about that freezing point. The Solver chooses the page. A reader must be able to open it without an account, a payment, or special permission.

This bounty buys that statement and that citation. It does not buy a new measurement.

## What you need to submit (Deliverables)

Submit one file named `answer.md`. The file is mandatory. It is UTF-8 Markdown. It is the only file in the Submission.

The file must do both of the following:

- State that the freezing point of water at 1 atmosphere is 0°C.
- Cite one absolute `http://` or `https://` URL that points at a public page about that freezing point.

The URL is a citation inside the file. The file is the deliverable. A link does not replace the file.

The statement may use `0°C`, `0 °C`, or `0 degrees Celsius`. Each of those wordings states 0 degrees Celsius. A different number does not.

A Submission is complete when `answer.md` is present and contains both the statement and the citation.

| Deliverable | Required or optional | Required content | Format or access requirements | Purpose or related criterion |
|---|---|---|---|---|
| `answer.md` | required | The 0°C freezing-point statement and one public reference URL | One UTF-8 Markdown file named `answer.md` | Carries the fact and the citation that acceptance checks |

## Acceptance Criteria

`answer.md` passes only when both of the following are true:

1. The file states that the freezing point of water at 1 atmosphere is 0 degrees Celsius. The accepted wordings are `0°C`, `0 °C`, and `0 degrees Celsius`. A different temperature does not pass.
2. The file contains a URL that points at a public page about that freezing point.

A `0` that appears only inside another number, such as `10` or `20`, or only inside a URL, does not state the freezing point.

A URL points at a public page when all of the following hold:

- The URL is an absolute `http://` or `https://` address.
- A reader can open the page without an account, a payment, or special permission.
- The page discusses the freezing point of water at 1 atmosphere.

A citation fails when the page is confirmed to be about another substance, confirmed to discuss freezing only at a different pressure, confirmed to require an account, a payment, or special permission, or confirmed to be a dead address.

One qualifying URL is enough. The file does not need a second source.

### Evidence, Provenance and Verification

The claim is a published physical fact, not a new experiment. The evidence is the cited page. A reader checks it by opening the URL and seeing that the page discusses the freezing point of water at 1 atmosphere.

The file's own statement must give the temperature as 0°C. The page shows that the citation is about that freezing point. No laboratory record is required.

A confirmed nonpublic, paywalled, irrelevant, or dead page fails the citation requirement.

## How is the winner selected?

A passing Submission meets every acceptance criterion and is not disqualified. Byte length is the number of bytes in the submitted `answer.md` file. The comparison uses those file bytes. It does not use a character count, a trimmed copy, or any other file.

The citation URL is the absolute `http://` or `https://` URL in `answer.md` that meets the citation requirement. When that file contains more than one such URL, the citation URL is the lexicographically smallest of them. Compare citation URLs as written in the file, in UTF-8 byte order. A proper prefix of a longer URL is smaller.

The Solver address is the lowercase Solver address for that Submission, under Elgora's existing Submission identity. Compare those lowercase addresses in UTF-8 byte order.

- If no Submission passes, there is no winner. The outcome is `no_valid_submission`.
- If one Submission passes, that Submission wins.
- If several Submissions pass, the Submission with the smaller `answer.md` byte length wins.
- If passing Submissions share that smallest byte length, the lexicographically smaller citation URL wins.
- If those citation URLs are also equal, the lexicographically smaller Solver address wins.

When any Submission passes, this order selects exactly one passing Submission. `no_valid_submission` is not the outcome in that case.

## Disqualification Conditions

A Submission is disqualified when `answer.md` is missing, or when that file is not UTF-8 text. A Submission that includes a private key, a seed phrase, or a credential is disqualified.

A Submission that fails the acceptance criteria does not pass. That failure is not a separate disqualification.

## Out Of Scope

This bounty does not buy a laboratory measurement. It does not buy the freezing point of another substance. It does not buy the freezing point of water at a pressure other than 1 atmosphere.