Friday 28 February 2014

Turn Fire Into A Snake!

Have you ever tried making a volcano model using baking soda and vinegar? Or mixing two different food colouring to get a new colour for your icing? If it never occurred that you are already a chemist in your own house, try remembering that each time you make a glass of Milo, or cook a meal, you are actually using principles of chemistry.

Let us explore and try to turn fire into a snake by doing an experiment using baking soda, sugar, methylated spirits and a lighter. You can use matches in case you don't have a lighter. 
What you need are two parts of sugar mixed with one part of baking soda. Mix it on a fireproof surface such as aluminium foil and put a few drops of methylated spirits. You can get it from pharmacies or maybe in your first aid kit. Then, ignite it with a kitchen lighter. To make it grow in shape, it is best if you put some sand as base before adding in the mixture of baking soda and sugar.
So, what do you think will happen? When the baking soda is heated to a specific temperature, carbon dioxide gas is released. Pressure will then build up which causes the black 'snake' to form. The 'snake' is black in colour due to the sugar being caramelized by the heat produced from the combustion. Try it out, it's cool! Now let's watch the video below.

As a safety precaution, have a pail of water nearby or do it near a sink. In case you panic you can throw the mixture into the pail or sink. Don't get burned or set your house on fire! This is a project which requires adult supervision.

With a pinch of adventurous enthusiasm, a tablespoon of science knowledge available online or in books, and a cup of safety precaution, you can turn your kitchen into a fun classroom for yourself and family members!

Shared by Izhana
Learning Specialist, Petrosains

Thursday 27 February 2014

It's Plastic, But You Can Eat It!

You know that plastics are everywhere.  There are probably a few plastic items within your reach while you're reading this articleUsually, the majority of what we know as plastics today are made from materials that are extracted from crude oil. We use many plastic products such as  in computers, toothbrushes and in every day home equipments.  

But have you ever heard of plastics made of milk? They are used to make buttons, decorative brooches, buckles, jewellery, fancy combs and even brush sets. Did you know that milk plastic was even used to make jewellery for Queen Mary of England? 

Let's try to make milk plastic out of hot milk and vinegar. First, heat one cup of milk in a pan for about 10 minutes. Carefully stir the milk using a spoon to ensure the heat is spread evenly. Then add 6 teaspoons of vinegar to the small bowl and stir it with a spoon for about a minute. By adding vinegar to the hot milk, white chunks should become visible in the mixture. The white chunks are curds. And the curds are actually milk proteins called casein.
The vinegar acts as an acid that will change the pH of the milk and causes the casein molecules to unfold and reorganize into a long chain, curdling the milk.  Finally, pour the milk through the strainer. Please be very careful because it will be hot! Left behind in the strainer is caseinNow just mold it into a shape or add some colour to it and it will harden in a few days.  
Now you can use them to make decorative items, toys or a brooch by adding a pin at the back. So there you go! Now you know how milk plastic is made. It's actually not to be eaten but it's good to know that it is safe and non-toxic. For example, wouldn't it be nice to know that things that go in your mouth, such as your toothbrush is made of milk plastic?

Maybe it sounds strange that plastic can be made from milk. This is why milk plastic is also called casein plastic!

You can also try this activity at Petrosains and have fun with our current theme, Nature's Kingdom!

Posted by Ayu
Learning Specialist, Petrosains

Thursday 20 February 2014

Mengapa 'Mencurah Air Ke Daun Keladi' Namun Ia Tetap Tidak Basah?

Mencanting pada lukisan batik bertujuan menutup bahagian motif  supaya ia akan tetap putih. Bahan yang digunakan untuk proses ini adalah campuran lilin dan damar. Lilin mempunyai sifat tidak larut dalam air. Begitulah yang diibaratkan dengan peribahasa melayu 'mencurah air ke daun keladi'. Walau sebanyak mana sekalipun air dicurahkan ke atas permukaan daunnya, ia tetap akan berada dalam keadaan yang segar dan tidak basah.

Ini adalah kerana bahagian atas setiap daun keladi dilitupi oleh satu lapisan kalis air yang dinamakan sebagai kutikel berlilin. Lapisan ini menghalang peresapan air keluar dan masuk melaluinyaKutikel merupakan lapisan bukan sel yang menyelaputi beberapa bahagian tumbuh-tumbuhan seperti daun dan batang pokok. Lapisan ini mampu menghalang kehilangan air melalui proses penyejatan. Lapisan ini tidak berwarna, maka cahaya matahari masih dapat menembusinya. Lapisan ini tidak membenarkan gas melaluinya, sebaliknya gas keluar dan masuk melalui bahagian bawah daun. Selain itu struktur daun ini membantu untuk melindungi daun tersebut daripada serangan serangga perosak.
Terdapat pelbagai jenis pokok keladi namun pokok keladi yang dimaksudkan adalah dari jenis Keladi Sebaring seperti yang ditunjukkan pada gambar di atas. Disebabkan saiz daun keladi  ini agak lebar dan besar, struktur urat daun  akan menyokong daun keladi supaya berada dalam susunan bentuk yang sesuai bagi memastikan ia menerima jumlah cahaya matahari yang sederhana untuk menjalankan fotosintesis. Urat juga berfungsi  menghalang  daun keladi dari menjadi layu.     

Kerana sifat lilin yang tidak larut dalam air dan keadaan kutikel berlilin pada permukaan daun  yang sebenarnya adalah punca daun keladi tidak basah walau sebanyak mana air sekalipun dicurahkan padanya. Begitulah juga maksud peribahasa ini iaitu seperti melakukan perbuatan yang sia-sia sahaja seolah-olah seseorang yang tidak mahu berubah setelah sudah berkali-kali memberikan nasihat kepadanya. 

Posted by Ayu
Learning Specialist, Petrosains

Monday 17 February 2014

2014 Winter Olympics

Image credit: Joy Siggers, Wikimedia Commons

The 2014 Winter Olympics kicked off to a grand opening ceremony at Fisht Olympic Stadium in Sochi, Russia on 7 February.  Sochi is a city in Krasnodar Krai, Russia that is located on the Black Sea coast near the border between Georgia/Abkhazia and Russia.   This Games is officially known as the XXII Olympic Winter Games.

How it began
Efforts to have a winter version of the Olympics started in 1908 when figure skating made an appearance at the Summer Games in London.  Organisers of the 1916 Berlin Games planned to introduce a ”Skiing Olympia” but their hopes were dashed due to the breakout of World War I.  After the War, the Games resumed in 1920 at Antwerp, Belgium with the return of figure skating and the addition of ice hockey.

The first Winter Olympics was inaugurated in 1924 at Chamonix, France but not before encountering objections from Baron Pierre de Coubertin, founder of the Modern Olympics, and Scandinavian countries. Eventually a compromise was reached and the International Olympic Committee sanctioned an “International Winter Sports Week”.  The event included Nordic skiing, speed skating, figure skating, ice hockey and bobsledding.  It was a huge success.

The 1994 Winter Olympics in Lillehammer, Norway ended the four-year Olympic cycle of staging both Winter and Summer Games in the same year and began a new schedule for the two Games to alternate every two years.

2014 Winter Olympics

A total of 98 events in 15 winter sport disciplines are being held.  The disciplines are:
1) Alpine Skiing
2) Biathlon
3) Bobsleigh
4) Cross-Country
5) Curling
6) Figure Skating
7) Freestyle Skiing
8) Ice Hockey
9) Luge
10) Nordic Combined
11) Short Track
12) Skeleton
13) Ski Jumping
14) Snowboarding
15) Speed Skating

Eighty-eight nations qualified to compete. Seven nations - Dominica, Malta, Paraguay, Timor-Leste, Togo, Tonga, and Zimbabwe made their debut.  Besides Timor-Leste, two other South-east Asian countries are also participating – Philippines and Thailand.  There is no ice or snow in these countries but yet they are competing!

Fast facts:
1. Michael Christian Martinez of the Philippines is a man of firsts - the first Southeast Asian to advance to the finals in a Winter Olympic game and also the first figure skater from Southeast Asia to compete in the Winter Olympic Games. 

2. Thailand's Vanessa Vanakorn or popularly known as Vanessa-Mae is the first woman athlete from Southeast Asia to compete in the Winter Games.  She is also a violinist. She is scheduled to compete in the women's giant slalom event of alpine skiing on Tuesday, February 18.

3. Wednesday, February 19 - another Thai athlete, Kanes Sucharitakul, will compete in the men's giant slalom event.

4. Debutant Timor-Leste is represented by Goutt Goncalves who will compete in Alpine skiing.

Do you envision Malaysia making its debut in any Winter Olympics?  The 2018 Winter Olympics will be at Pyeongchang, South Korea. We hope it’s sooner than later, considering climatic changes taking place globally!

Friday 14 February 2014

'Butterfly' Itu Kupu-kupu & 'Moth' Adalah Rama-rama

Keliru tetapi ia adalah fakta.  Ramai yang beranggapan sebaliknya tetapi ini adalah kebenarannya. Ada juga segelintir yang langsung tidak pernah mengambil berat tentang perkara ini.  Apabila setiap kali ternampak ia berterbangan, terus dikatakan ia adalah rama-rama walaupun sebenarnya ia adalah seekor kupu-kupu. Tetapi bagaimana untuk mengetahui  samada ia adalah kupu-kupu atau rama-rama?

Butterfly itu ialah kupu-kupu dan bukannya rama-rama. Moth ialah rama-rama. Acapkali sekiranya ia kelihatan menghinggapi bunga pada waktu petang, itu adalah kupu-kupu. Kupu-kupu adalah diurnal ataupun aktif di siang hari manakala kebanyakkan rama-rama adalah nokturnal ataupun aktif pada waktu malam.
Secara fizikalnya, kupu-kupu memiliki sayap yang 'cantik' kerana berwarna-warni. Kupu-kupu mempertahankan diri dengan memberikan isyarat melalui warna sayapnya yang terang terhadap pemangsa. Manakala rama-rama pula memiliki sayap yang tidak berwarna terang. Selalunya rama-rama lebih cenderung memiliki warna-warna semulajadi seperti  coklat, kelabu, hitam dan coklat kehitaman.

Tetapi perbezaan di antara kedua-duanya boleh juga dikenalpasti berdasarkan bentuk sesungut. Kupu-kupu biasanya mempunyai sesungut yang lurus dan berbentuk seperti belantan di hujungnya. Rama-rama pula mempunyai sesungut lurus tetapi berbulu. Perhatikan gambar di bawah untuk penjelasan yang lebih terperinci.

Selain itu,  sayap kupu-kupu terlipat tegak semasa ia dalam keadaan rehat. Rama-rama pula akan mengembangkan sayapnya dalam keadaan rehat. Cuba teka samada gambar di bawah adalah seekor kupu-kupu atau rama-rama?

Posted by Ayu
Learning Specialist, Petrosains

Friday 7 February 2014

Magic In Your Kitchen!

Let's do magic by using something that you can get from your kitchen! But is it really magic or is it science? Science magic tricks look like "magic," but there is a secret behind the special effects. The secret is a scientific principle or concept from maybe chemistry or physics that makes it look like a 'magic' trick. The great thing is these 'magic' tricks can be used to demonstrate or teach a scientific concept like chemistry in a fun way. Here is a science magic trick using 'red cabbage juice' as a natural pH indicator that changes colors according to the acidity and basicity of the solution! 

But how do you do it? Just peel off six red cabbage leaves and put them in a blender filled half full with water. Then pour the purplish cabbage liquid through a strainer to filter out all of the big chunks of cabbage. Keep the red cabbage juice in a bottle and store it in a refrigerator.

Red cabbage contains a water-soluble pigment called anthocyanin that changes color when it is mixed with an acid or base. The pigment turns red in acidic environments and turns bluish-green in alkaline environments. In chemistry, pH is a measure of the acidity or basicity of a solution.

Now comes the interesting part! Take a small container and fill it with lemon juice. Add red cabbage juice to the container and notice the colour change to red, which indicates that lemon juice is acidic. Watch the video! 

Next, try doing the same with soap solution in a separate container. Add red cabbage juice to it. Notice how the liquid turns to bluish-green, indicating that the soap solution is alkaline. 

Repeat your experiments! Try it with other solutions like detergents and vinegar. You'll find the answer immediately, as to whether it is acidic or alkaline. Usually, an acid is a substance with a sour taste. It also has a pH value of less than 7. However, an alkaline tastes bitter with a pH greater than 7.

Did you know that plants that have colours have pigments in them? Some plants' pigments can react with acid and alkaline and will change colour accordingly. There are many other plants that can be a natural pH indicator too. Next you can try making natural pH indicators using dragon fruit, black berries, grapes and hibiscus too!  

You can also try this at Petrosains and have fun with our current theme, Nature's Kingdom!

Posted by Ayu
Learning Specialist, Petrosains

Aromaterapi Dalam 'Sudah Gaharu Cendana Pula'

Peribahasa 'Sudah Gaharu Cendana Pula' adalah pembayang kepada baris pemaksud iaitu 'Sudah Tahu Bertanya Pula'. Maksudnya lebih mudah diterangkan mengenai seseorang yang sudah mengetahui tentang sesuatu perkara tetapi pura-pura buat tak tahu malah ingin bertanya lagi.
Kaitan maksud peribahasa ini dapat dilihat dengan jelas daripada perihal gaharu dan cendana. Gaharu dan cendana, kedua-duanya adalah dua jenis tumbuh-tumbuhan yang berbeza atau berlainan spesies tetapi mempunyai persamaan yang ketara dari segi penggunaaannya di mana kedua-dua tumbuhan ini digunakan untuk membuat minyak wangi kerana ia mampu mengeluarkan bau yang harum. Secara fizikalnya, diketahui gaharu adalah lebih wangi dari cendana. Jadi, peribahasa ini mengibaratkan mengapa kita perlu mencari cendana jika sudah memperoleh gaharu.

Pokok gaharu (Aquilaria malaccensis) ataupun 'agarwood' dan turut dikenali sebagai 'oud' merupakan sejenis pokok yang hidup subur di hutan tropika. Semua bahagian pokok gaharu, dari batang, kulit, daun, bunga, buah dan rantingnya digunakan untuk menghasilkan produk minyak wangi. Manakala pokok cendana (Santalum album) ataupun 'sandalwood' ialah sejenis pokok dari keluarga Santalaceae merupakan sejenis tumbuhan parasit iaitu terpaksa menumpang pada tumbuhan lain untuk hidup kerana ia sendiri tidak mampu untuk menyokong pertumbuhannya kerana ia mempunyai sistem akar yang lemah. 

Sekarang, mari kita kupas apa kaitannya peribahasa di atas dengan aromaterapi?Aromaterapi merupakan istilah generik bagi satu jenis rawatan alternatif untuk tujuan tertentu menggunakan bauan aromatik yang diperolehi dari minyak pati dan resin tumbuh-tumbuhan. Bauan aromatik yang dimaksudkan diperolehi secara semulajadi dari sejenis sebatian organik yang dikenali sebagai terpenes.
Terpenes diekstrak melalui  proses penyulingan dan mempunyai sifat mudah meruap. Kayu gaharu berwarna kehitaman dan mengandungi resin khas digunakan untuk membuat minyak wangi dan setanggi manakala kayu cendana yang bewarna kuning digunakan dalam industri wangi-wangian. Dari sudut komposisi kimianya, terpenes merupakan hidrokarbon tidak tepu dan mempunyai formula am ( C5H8 )n. Terpenes mudah diubahsuai secara kimia melalui tindakbalas dengan oksigen di udara. Ini menyebabkan bauan aroma ini akan  turut berubah mengikut masa. 

Sebagai kesimpulannya, tumbuh-tumbuhan lain mungkin mempunyai profil terpenes yang berbeza di mana ia memberikan kepelbagaian aroma  seperti yang boleh diperolehi dari kayu putih, kayu manis, limau dan bunga-bungaan yang  turut diaplikasikan di dalam minyak wangi yang sering kita gunakan seharian.

Posted by Ayu
Learning Specialist, Petrosains