2021 STEM Challenges

This event series is an opportunity for high school and college students to participate in fun and hands-on weekly challenges on a range of science, technology, engineering, and mathematics (STEM) topics. The competition is being organised by the Australian National University (ANU).

Registration is essential and will stay open throughout the activity period.

How it works

  • Students need to register to participate.
  • Every Monday, challenges will be released by email to all registrants and will also be published on this website. Students will have one week to complete each challenge(s), with answers/photos due on Sunday of the same week.
  • Each of the challenges will draw on a different element of STEM and may require you to take photos, answer questions or build/design something to complete the challenge.
  • In some weeks, there might be two challenges with different STEM topics released, students can choose to do one or both.
  • Only one submission per challenge will be accepted and counted for each participant.
  • Each week, the submissions will be judged by a panel of ANU staff and voted on.
  • Winners will be announced on the Tuesday following the submission deadline and will be notified by email and will also appear on our social media pages.

Prizes

  • Winners will receive a Winner's Certificate and a surprise prize.
  • All registrants who submit at least one challenge over the 7 weeks of challenges will also receive a printable online Certificate of Participation from the Australian National University. The certificate of participation is not part of the AQF.

Challenge dates

1st week challenge: 2 – 7 November 2021 (Due to an ANU staff holiday Monday)

Melting Ice and Ocean Water Density

The modern ocean moves like a giant conveyor belt. In winter, as ice is forming in the North Atlantic sea, salt is pushed out of the ice creating a layer of water that is very salty and very cold. Because cold water is more dense than warm water, this layer sinks to the deep ocean. This water enters a current that carries it to the Pacific Ocean where it warms and rises to the surface before travelling back to the North Atlantic where it cools and sinks again. If a large amount of fresh water is added to this system, the conveyor belt could slow because freshwater is less dense than salty water and would not be able to sink to flow through the deep ocean.

Make a video of yourself performing the experiment. After finishing the activity, you can compare the situations in the cups to the "real" ocean.

Materials you will need

· 2x glass jugs or bowls (same size for both)

· Salt

· Timer (stopwatch / timing app on a phone)

· Ice chips (500ml in the beaker)

· Liquid food dye

Here is your challenge

  1. Half fill the two glass jugs/bowls with room temperature water and several drops of food dye. Stir salt (about 3 tablespoons) into only one of the bowls until it is completely dissolved.
  2. Place the same amount of ice chips into both jugs/bowls and start a stopwatch/note the time.
  3. When it becomes obvious that one is indeed melting faster, a drop of food dye can be added on each of the ice cubes to colour the melt water.
  4. Record the time until each of the ice cubes has melted completely.

Note: Before you start your experiment, make a prediction which ice cube will melt faster, the one in salt water or the one in fresh water? Why?

What to submit

  1. Make a video (max 30 seconds): show us your experimental setup, and answer: which one melted faster? why? and why is this important in terms of ocean circulation?
  2. Post your video to Instagram and tag @ScienceANU (not #hashtag). If you don't have Instagram or would prefer to email us, then just email your photo and caption to science@anu.edu.au. Note: make sure to turn off your “Private account” setting on Instagram before posting your submission and tag us. You can turn it back on soon after you receive our confirmation.
  3. The week one challenge submission closes on 11.59pm on Sunday 7th November of your local time.

The winner will be announced on Tuesday 9th November. The winning entry will be posted to our Facebook and Instagram and on the website. The winner will be notified by email. Other submissions may be included in an Instagram story.

Winner: Riley

2nd week challenge: 8 – 14 November 2021

This week we have two challenges created for you. You can complete one or both. To be in the running for a prize this week you must complete just one of the challenges, but to double your chances of winning complete both!

This week’s submissions close at 11.59pm on Sunday 14th November of your local time. The winner for both challenges will be announced on Tuesday 16th November. Follow us on the Facebook and Instagram @ScienceANU to check out the last week's winning entries and other submissions on Tuesday 9 Nov. The winners will also be notified by email.

Option #1: Designing a solar car

Here at ANU, we are proud to have the ANU Solar Racing Team who compete in the Bridgestone World Solar Challenge every 2 years. They fund, design, build and race a solar car. In the challenger class, the goal is to go as fast as possible. When building a car like this, there are many important design considerations to make in order to maximise the car’s efficiency. When building a car like this, there are many important design considerations to make in order to maximise the car’s efficiency. Aspects of the car like the number of wheels, the area of the solar array, the shape of the occupant cell are all carefully thought out.

Here is your challenge

1. Do some research into solar cars, have a look at ANU Solar Racing at ANU Solar Racing or other cars in the BWSC.

2. Make a drawing of a solar car of your design. Include some labels and size measurements.

What to submit

1. Take a photo of yourself with your solar car design.

2. Post your photo to Instagram and tag @ScienceANU, or email your photo and caption including your name to science@anu.edu.au.

Option #2: Biodiversity Challenge

Understanding biodiversity is increasingly important as climate change affects the habitats of many species. This is an area where citizen science – where scientists use data collected by ordinary citizens – can have a big role. This allows scientists to monitor biodiversity in local habitats on a much larger scale than they could themselves.

Here is your challenge

1. Download the iNaturalist app (it’s free).

2. Find wildlife in your local area, and find 5 different species and aim for as much diversity as possible.

3. Use iNaturalist to take a picture of each species you find and record its location. Your 5 species should include:

a. At least one plant

b. At least one invertebrate

c. At least one vertebrate.

4. Use iNaturalist to identify each species (or come up with your best guess if the identification is uncertain). If you wish, you can share your observations on iNaturalist so that scientists can access them.

Note: if you have trouble downloading/using this application, it’s all good, you can still participate in this challenge by following the submission instruction below.

What to submit

1. Create a 1-page collage of your photos and label each photo with the species name and whether each species is native to Australia or introduced. For the students in India, the same rule applies but identifying species native to India or introduced.

2. Post your photo to Instagram and tag @ScienceANU, or email your photo and caption including your name to science@anu.edu.au.

3rd week challenge: 15 – 21 November 2021

This week you also have two challenges to choose from.

The submissions for both challenges close at 11.59pm on Sunday 21st November of your local time. The winners will be announced on Tuesday 23rd November.

Option #1: Making models of molecules

The molecules that are the building blocks of everything in the world (including us) have a range of particular shapes that describe how they link together.  For example, a water molecule known as H2O is made up of 2 hydrogen atoms and 1 oxygen atom. Water will always have 2 times the number of hydrogen atoms as oxygen atoms.

Here is your Challenge

1. Here are the chemical formulae of six molecules: CO2 (carbon dioxide), BF3 (boron trifluoride), NH3  (Ammonia), CH4 (methane), PF5 (Phosphorus pentafluoride) and SF6 (Sulfur hexafluoride)

2. Choose one of these molecules and Google it to learn about its 3D structure.

3. Once you have researched your molecule, use materials that you can find at home to make a 3D model of it (As examples, you could use marshmallows and toothpicks, or flowers with their stems poked into a tomato – see how inventive you can be!)   

What to submit

1. Send us a photo of your 3D creation of your chosen molecule, in the photo please also tell us the formula of the molecule and what kind of 3D structure it has (For example, O3 (Ozone) is a trigonal planar molecule, for help with identifying molecule structure check out this link).

2. Post your photo to Instagram and tag @ScienceANU, or email your photo and caption including your name to science@anu.edu.au

Option #2: Hair dryer ping pong ball levitation

Ever made a ball hover? Wonder why it is hovering?

It’s because the air pushes up on the ball, and the force of gravity pulls down on the ball – where those forces two balance is where the ball hovers. The ball also stays hovering because air rushing past the ball to its sides and curls around the ball holding it in place like two cupping hands. When we tilt the blower those cupping hands of air hold it up.

You will need

• Hair dryer. CAUTION: Hairdryer needs to set on cool air not hot.

• Ping pong ball. Don’t have a ping pong ball? That’s okay! See what else you have around the house that you can get to hover in your air stream. This experiment can even be done with a leaf blower and inflatable ball for a more extravagant outcome!

Here is your challenge

1. Keep hair drier blow cool air. If your dryer doesn’t have this setting, take care the ball (or other item) doesn’t get too hot.

2. Turn on the blower aiming it straight up and place the ball about 10cm above in the stream of air – it should start to hover!

What to submit

1. Take a photograph of you with your object as it hovers.

2. Post your photo to Instagram and tag @ScienceANU, or email your photo and caption including your name to science@anu.edu.au .

4th week challenge: 22 – 28 November 2021

This week we have also got two challenges for you. We will have one winner for each challenge, again you can choose to complete both challenges or just one of them. We are having so much fun viewing all your submissions, we can’t wait to see what you submit this week!

This week’s submissions close at 11.59pm on Sunday 28th November of your local time. The winners will be announced on Tuesday 30th November.

Option #1: Working model of the lungs

Take a deep breath. In through the nose, out through the mouth. As you breathe in, your lungs fill with air and expand, causing your chest and stomach to rise. As you breathe out, the air exits your lungs, and they deflate. Most of us repeat this process approximately 22,000 times a day, usually without thinking about it.

You will need

  • 1 x empty 1-liter bottle
  • 3 x balloons
  • 2 x straws
  • Strong tape
  • Play-dough, clay, blu tack (anything you can find to make an airtight seal)

Here is your challenge

  1. Put the neck of a balloon around the end of each of the two straws and tape it securely on (you should have two straws each with a balloon on the end).
  2. Cut the bottom off your 1-liter bottle.
  3. Put the two straws inside the bottle with the balloon end inside the bottle, and the other end of the straws sticking through the neck of the bottle.
  4. Use your play-dough, clay, blu tack, to create an airtight seal around the mouth of the bottle where the two straws are sticking out. You don’t want any air to get out other than what comes through the straws.
  5. Tie the opening of the third balloon (where you would inflate the balloon) and cut the top part off (the round part of the balloon itself).
  6. Take this balloon and stretch the opening you made over the opening at the bottom of the 1-liter bottle and tape this balloon tightly in place.
  7. Pull on the balloon you have taped to the bottom of your bottle. Your balloons inside should inflate. Gently release the balloon and your balloons inside should deflate. You have made a working model of the lungs!

What to submit 
1. Send us a photo or video of your working lungs, in the photo or video please also share your favorite fact about the lungs.  
2. Post your photo to Instagram and tag @ScienceANU, or email your photo and caption including your name to science@anu.edu.au .

Option #2: Weathering, erosion and deposition experiment

Weathering, erosion and deposition are constantly changing the shape of our environment. Weathering breaks down the Earth's surface, erosion moves the weathered rock and deposition is when that sediment settles in a new location.

You will need

  • Damp sand
  • Water jug
  • Baking tray (a few centimetres deep)
  • Something to raise one side of the pan (e.g. a book)
  • Tea towel (or do the experiment outside and you won’t need this!)

Your challenge

  1. Spread ~1-2cm thickness of the damp sand onto one half of the baking tray – you can even create your own topography by building hills and valleys with the sand!
  2. Prop up one end of the baking tray to create a small slope.
  3. Place 2-3 ice cubes in the top corners of the baking tray in a section of flat sand.
  4. Create a narrow river bed in the sand from the top of the baking tray to the bottom of your sand covering. Do this by running your finger through the damp sand.
  5. Pour a stream water from the water jug gently into the top of your river. Observe how the water erodes the sides (called the banks) of the river and transports the sand down-stream. Once you have observed this erosion, stop pouring and observe the sediment that has been deposited. Is there a difference in the size of the sediment that has been transported further “down-stream”?

What to submit

  1. Send us a photo or video of your eroded sand, in the photo or video please answer the question “is there a difference in the size of the sediment that has been transported further down-stream? Why has this happened?”
  2. Post your photo to Instagram and tag @ScienceANU, or email your photo and caption including your name to science@anu.edu.au .

    5th week challenge: 29 November – 5 December 2021

    This week your two challenges are a crypto caption challenge and a memory challenge.

    The submissions close at 11.59pm on Sunday 5th December of your local time. The winners will be announced on Tuesday 7th December on our Instagram and this website.

    Option #1: Crypto captions

    Cryptography and codes have been used throughout history to keep secret messages safe from eavesdroppers. They take a message you want to send, and convert it into a jumbled message, called a ciphertext, that can’t be understood without reversing the process. 

    As time goes on, people will discover ways of breaking the old codes, and so they are replaced by new, stronger codes. Modern codes operate not on letters and words, but on bits and bytes inside computers. To keep it simple, we’ll be sticking with just jumbling letters this time. 

    Your challenge is simply to follow the instructions. Filling out this table may help:

    A

    B

    C

    D

    E

    F

    G

    H

    I

    J

    K

    L

    M

    N

    O

    P

    Q

    R

    S

    T

    U

    V

    W

    X

    Y

    Z

    Here is your challenge

    1. Decode instructions 2 and 3.
    1. UOHRHMTJUO J NWTFWN HI HXAWKRN (FS THPMOZQ J ZFSW), ROW IFTNR ZWRRWT HI WJKO HXAWKR NUWZZFSM HPR J EHTV ITHG ZWIR RH TFMOR. IHT WBJGUZW, FI QHP EJSRWV RH NUWZZ HPR "KHVW", QHP KHPZV PNW KPNOFHS, HSFHS, VFKW, JSV WMM, ZFCW F VFV FS GQ UOHRH.
    1. ROWS, WSKTQUR ROJR EHTV PNFSM HPT KHVW. ROFN EFZZ XW HPT KJURFHS.

    Tips:

    The letters of the alphabet are secretly paired, and then you swap each letter with its partner in the message. To decrypt it, if you know the pairing, you just swap them again.

    Without knowing the pairing, you can break it by counting the letters “frequency analysis” and swapping the most common letter with the most common letters in the English alphabet.

    >> view solution

    What to submit

    1. Send us a photo of your decoded message (don’t forget to be creative with your submission). Photos will be judged by a panel of ASD – ANU Co-Lab.
    2. Post your photo to Instagram and tag @ScienceANU, or email your photo and caption including your name to science@anu.edu.au.

    Option #2: Working memory challenge

    Working memory is a type of short-term memory that holds information temporarily. Think of it like a sticky note in your brain that allows you to remember information while you are using it. For example, you are using your working memory when your teacher asks you to carry out instructions such as “Get out your math textbook, open up to page 23, and answer question number 4”.

    You will need

    • Standard deck of cards
    • Pen and paper
    • 2 participants

    Here is your challenge

    Phase 1
    Task 1: Person 1 shuffles the card deck and hands to person 2; Person 2 has 3 minutes of studying the cards to remember the order and cannot change the order of the cards or record information anywhere. After 3 minutes, person 2 writes down as many card values in order as they can remember. Person 1 checks person 2’s results and records the number of consecutive correct values without error. Repeat task for person 1.

    Task 2: Person 1 shuffles the card deck and hands to person 2; Person 2 has 3 minutes of studying the cards to remember the order and cannot change the order of the cards or record information anywhere. After 3 minutes, person 2 writes down as many card values and corresponding suits in order as they can remember. Person 1 checks person 2’s results. Repeat task for person 1.

    Phase 2
    We are going to try tasks 1 and 2 again but first let's learn a little bit about “chunking”. Chunking is the process of grouping bits of information together to make them easier to remember. For example, a phone number 47113248 is hard to remember as just a strong of numbers. But, we can chunk this number into 47-11-32-48 or even 471-132-48 and the number becomes a lot easier to remember. We take the number from 8 individual numbers to 3-4 groups of information.

    If you are working with a list of vocabulary words, for example, you might create small groups of words that are similar or related to one another. A shopping list might be broken down into smaller grouping based on whether the items on the list are vegetables, fruits, dairy, or grains.

    Have a look at this link to learn more about chunking.

    Now repeat tasks 1 and 2 using chunking strategies.

    What to submit:

    1. Send us a photo of your results from phase 1 and phase 2 (don’t forget to be creative with your submission).
    2. Post your photo to Instagram and tag @ScienceANU, or email your photo and caption including your name to science@anu.edu.au.

    6th week challenge: 6 – 12 December 2021

    The challenge(s) will be released on Monday 6 December 2021

    7th week challenge: 13 – 19 December 2021

    The challenge(s) will be released on Monday 13 December 2021

    Register

    Week 1 challenge

    Week 2 challenges

    Week 3 challenges

    Week 4 challenges

    STEM Challenges 2020

    Have a question?

    The challenges have been created through a collaboration between the ANU College of Science, the ANU College of Health and Medicine, and the ANU College of Engineering and Computer Science. Please contact us via the email below if you have any questions.

    Terms and conditions

    1. ANU College of Science and ANU College of Health and Medicine (ABN: 52 234 063 906)
    2. Information on how to enter the ANU Science Case Study Competition forms part of these Terms and Conditions.
    3. Entry is open to all Australian residents and a group of international students.
    4. Entry to the competition is via the ANU College of Science STEM Challenges web page.
    5. There is no entry fee for the competition.
    6. ANU College of Science and ANU College of Health and Medicine Staff and their immediate family are excluded from participation
    7. There is (1) prize available for the best entry each week.
    8. The ANU College of Science and the ANU College of Health and Medicine reserve the right to modify or remove any prizes if required, or not to award a prize.
    9. The prize must be taken as stated and no compensation will be payable if the prize winner is unable to use the prize as stated. The prize is not transferable to another person or exchangeable for other goods and services and cannot be redeemed as cash.
    10. The entrant will be solely responsible for any costs or taxes incurred as part of the competition, or claiming of the prize, including but not limited to any taxes.
    11. Prize winners will be notified in writing (email) on the Tuesday following the submission deadline.
    12. Each participant is only allowed one submission per challenge.
    13. By entering the competition, you declare that the submitted work is entirely your own.
    14. The ANU College of Science and the ANU College of Health and Medicine reserve the right to withdraw applications at any stage for any reason determined appropriate by the ANU Colleges of Science and the ANU College of Health and Medicine.
    15. The ANU College of Science and the ANU College of Health and Medicine reserve the right to extend or modify the closing date.
    16. Submissions will be marked by a panel of judges chosen by the ANU College of Science and the ANU College of Health and Medicine.
    17. The ANU College of Science and the ANU College of Health and Medicine reserve the right to determine the final outcome of the competition, and to name and order winners and prizes.
    18. By entering the competition, all entrants and their guardians (where applicable) understand and give permission to the ANU College of Science, the ANU College of Health and Medicine, ASD-ANU Co-Lab and sponsors to use the winners name, video/photo submission, likeness and work for promotional purposes, and other purposes deemed appropriate.
    19. The concerned parties also understand and facilitate consent to measures covered under https://services.anu.edu.au/marketing-outreach/anu-identity/anu-audio-visual-release-form
       
    20. Participants agree that the ANU College of Science and the ANU College of Health and Medicine, ASD-ANU Co-Lab and sponsoring entities are not liable for any damages or losses arising from the competition.
    21. All submitted work is subject to the ANU College of Science and the ANU College of Health and Medicine Privacy Policy.
    22. Incomprehensible and incomplete entries will be deemed invalid.
    23. The ANU College of Science and the ANU College of Health and Medicine reserve the right to verify the validity of entries and to disqualify any entry which in the opinion of the ANU College of Science and the ANU College of Health and Medicine, includes objectionable content, profanity, potentially insulting, inflammatory or defamatory statements, disqualify any entrant who tampers with the entry process, who submits an entry that is not in accordance with these terms and conditions of entry or who has, in the opinion of the ANU College of Science and the ANU College of Health and Medicine, engaged in conduct in entering the promotion which is fraudulent, misleading, deceptive or generally damaging to the goodwill or reputation of the promotion and/or the ANU College of Science and the ANU College of Health and Medicine. The ANU College of Science and the ANU College of Health and Medicine reserve the right to disqualify a winner if the ANU College of Science and the ANU College of Health and Medicine become aware that the winner and/or the winner’s entry is of a type described in this clause.
    24. The ANU College of Science and the ANU College of Health and Medicine accept no responsibility for any late, lost or misdirected entries including delays in the completion of tasks due to technical disruptions, network congestion or for any other reason.
    25. The ANU College of Science and the ANU College of Health and Medicine’s decision is final and the ANU College of Science and the ANU College of Health and Medicine will not enter into correspondence regarding the result or winning entries.
    26. In the case of the intervention of any outside act, agent or event which prevents or significantly hinders the ANU College of Science and the ANU College of Health and Medicine’s ability to proceed with the competition on the dates and in the manner described in these terms and conditions, including but not limited to vandalism, power failures, tempests, natural disasters, acts of God, civil unrest, strike, war, act of terrorism, the ANU College of Science and the ANU College of Health and Medicine may in its absolute discretion cancel the competition and recommence it from the start on the same conditions, subject to any directions given under State Regulation.
    27. The ANU College of Science and the ANU College of Health and Medicine reserve the right in its sole discretion to disqualify any individual they believe has breached any of these conditions, or engaged in any unlawful or other improper misconduct calculated to jeopardise the fair and proper conduct of the promotion.
    28. The ANU College of Science and the ANU College of Health and Medicine collect personal information about you to enable you to participate in this promotion.
    29. All certificates (including winners’) are not an AQF certificate.