Terms of Use.

Particle HSC ("Particle", "we", "us") is a sole trader business based in New South Wales, Australia. Particle is an independent study tool. It is not affiliated with, endorsed by, or connected to the NSW Education Standards Authority (NESA), the NSW Department of Education, or any school.

• You must be at least 13 years old.
• If you are under 18, you confirm that a parent or guardian has agreed to you using Particle on these terms, and that any payment is made with the permission of the person whose card is used.
• You must give an email address you control. We use it to secure your account and to send the notices these terms describe.

Particle is a practice tool for NSW HSC Physics and Chemistry. You answer exam-style questions, and an artificial intelligence marker returns a mark, a per-mark breakdown, feedback and a worked solution. Particle also offers notes, analytics and exam planning built from your own answers.

Particle is a study aid. It does not replace your teacher, your school's assessment, or the official syllabus, and it makes no promise about any exam result, mark, band, ATAR or offer.

• One account per person, used only by you. Do not share your login or let someone else use your account.
• Particle allows one signed-in device at a time. Signing in on a new device signs out the others.
• You are responsible for everything done through your account. Tell us at once if you think it has been accessed by someone else.
• We may refuse, suspend or close an account that breaches these terms, that we reasonably believe is automated, shared or fraudulent, or where the law requires it.

Particle exists to help you learn. When you use it you agree that you will:

• use it to practise and to check your own working, then learn from the feedback;
• not submit Particle's worked solutions, feedback or notes as your own work in any assessment;
• not use Particle during any exam, test or assessment where outside help is not permitted.

Misuse of AI assistance can breach your school's rules and NESA's rules on malpractice. You are responsible for how you use what Particle gives you.

Marks and feedback are produced by an artificial intelligence model working from marking criteria we write in the style of HSC marking guidelines. We check its output before it reaches you, we audit it against real marking guidelines, and you can ask for a second opinion (a re-mark) on any answer. It is still a model: it can misread working, miss a valid method, or be a mark too generous or too harsh. Treat every mark as a strong guide and not as a result. Where it matters, check against your syllabus and your teacher. See How Particle uses AI.

The free tier includes up to 5 AI-marked written answers per rolling 24 hours and unlimited multiple choice. We may adjust the free allowance from time to time; the current figure is always shown on the Premium page.

Particle Unlimited is a paid subscription at A$29.99 per month, or the price shown to you at checkout, in Australian dollars. On it:

• It renews automatically every month and is billed in advance until you cancel. You will be told the price, the renewal and how to cancel before you pay.
• Payments are processed by Stripe. We never see or store your full card details.
• You can cancel at any time from Settings (Manage billing), which opens your Stripe billing portal. Cancelling stops future charges. You keep Unlimited until the end of the period you have already paid for.
• "Unlimited" marking carries a fair-use ceiling of 30 AI-marked written answers per rolling 24 hours, which is several times a heavy study day. Multiple choice is never limited.
• If a payment fails, we may retry it. If it keeps failing, Unlimited ends at the end of the period already paid for and your account returns to the free tier. Nothing is deleted.
• We may change the subscription price. We will email you at least 14 days before a change takes effect, and it will only apply from your next renewal. If you do not want the new price, cancel before then.

Because you can cancel at any time and keep what you paid for, we do not refund the current period when you simply change your mind. There are two exceptions.

• Our own promise: if Particle is not working for you in a way that stops you using what you paid for, and we cannot fix it within a reasonable time, we refund the current billing period.
• Your rights under the Australian Consumer Law, set out in section 9, which apply regardless of anything in these terms.

To ask for a refund, email particlehsc@gmail.com from the address on your account. Refunds go back to the card you paid with, through Stripe.

Our services come with guarantees that cannot be excluded under the Australian Consumer Law. For major failures with the service, you are entitled to cancel your subscription and to a refund for the unused portion, or to compensation for its reduced value. You are also entitled to be compensated for any other reasonably foreseeable loss or damage. If the failure does not amount to a major failure, you are entitled to have problems with the service fixed in a reasonable time and, if this is not done, to cancel and obtain a refund for the unused portion. Nothing in these terms excludes, restricts or modifies those rights.

• The questions, marking criteria, worked solutions, feedback text, notes, figures, software and design on Particle are owned by us or licensed to us and are protected by copyright. We grant you a personal, non-transferable licence to use them for your own study while you have an account. See the Copyright page for what is and is not allowed.
• The answers you write and the photos of handwriting you upload remain yours. You grant us a licence to store, process, mark and display them to you, and to use them in de-identified form to check and improve the marking. We do not publish your answers.
• If you send us feedback or a question through the Contribute feature, you allow us to use it, edit it and publish it on Particle without payment, and you confirm it is your own work.

You must not:

• copy, scrape, download in bulk, or systematically record the question bank, by hand or with any tool, script, extension or AI agent;
• share, sell or republish our content, share your account, or get around the free-tier limits, the fair-use ceiling or the one-device rule;
• reverse engineer the service, probe or overload it, or interfere with other users;
• upload anything unlawful, harmful, hateful, or that infringes someone else's rights, or include another person's personal information in an answer;
• use Particle's content to train or evaluate a machine-learning model or to build a competing product.

We may suspend or close an account used in these ways. Where the breach is deliberate, any unused subscription period is forfeited, subject always to section 9.

We aim to keep Particle available and accurate, but it is provided as it is at the time you use it. Features may change, be added or be withdrawn, and the service may be briefly unavailable for maintenance or for reasons outside our control. Where a change materially reduces what a paying subscriber receives, section 8 applies.

To the extent the law allows, and except for the rights in section 9: we are not liable for any indirect or consequential loss, including loss of marks, exam results, opportunities or income; our total liability to you for any claim connected with Particle is limited to the greater of the fees you paid us in the three months before the claim and A$50; and you accept that decisions about your study, your school work and your exams are yours.

• You can stop using Particle at any time. To delete your account and the data attached to it, email particlehsc@gmail.com from your account address.
• We may end this agreement and close your account for a serious or repeated breach of these terms, or if we withdraw the service. Where we withdraw the service, paying subscribers receive a refund for any unused period.
• Sections 5, 9, 10, 11 and 13 continue to apply after the agreement ends.

How we collect and handle your personal information is set out in the Privacy Policy, which forms part of these terms.

We may update these terms. For a change that affects your rights or what you pay, we will email you or show a notice in the app at least 14 days before it takes effect. Continuing to use Particle after that date means you accept the change. If you do not, stop using Particle and, if you are subscribed, cancel before the change applies.

These terms are governed by the laws of New South Wales, Australia. If something goes wrong, email us first and we will try to sort it out with you directly. If we cannot, either of us may take the matter to the courts or tribunals of New South Wales. Nothing here stops you from contacting NSW Fair Trading or the Australian Competition and Consumer Commission.