The egg float experiment

Do you have curious kids? Follow the simple steps to this egg float experiment with them and it will teach the kids how it floats, then sinks. They'll be amazed!

Number of players:

1+

What you need:

• egg
• water
• salt
• a glass
• spoon

Activity:

Fill a glass half full with water.

Next, place an egg into the water and help your child notice that the egg sinks.

This is because it is more dense than the water.

Start adding salt to the water one tablespoon at a time and gently stir it into the water.

Eventually, the egg will start to float.

One question is how much salt do you have to add to get your egg to float?

Now, have your child slowly add a cup of fresh water to the same glass with the floating egg and watch what happens.

It will start to drift back towards the bottom.

How much fresh water do you have to add to get the egg to sink to the bottom? Why does this happen?

Adding salt to the water squishes more molecules into the water.

This makes the water more dense.

When there was no salt in the water, the egg was more dense than the water and it sank.

Adding salt to the water makes the water more dense than the egg which makes the egg float.

If you weigh a cup of saltwater and a cup of fresh water, the saltwater will weigh more than the fresh water even though it is taking up the same amount of space (a cup).

This is because the saltwater is more dense than the fresh water.

Wave in a bottle experiment

Explore the wonders of how nature works with wave in a bottle, a fun science experiment and learning game. Kids will discover how and why water behaves and will be amazed at the power of the natural world. Kick start a possible love of science with this project today.

Number of players:

1+

What you need:

• empty plastic bottle and cap
• vegetable oil
• water
• food colouring

Activity:

Wash a bottle and take off the label by soaking it in hot water.

Fill the bottle with 3/4 cup of water.

Add a few drops of food colouring.

Pour 1 cup of oil into the bottle.

Screw the cap on.

Roll the bottle on its side and let it settle for a few minutes.

The water will sink to the bottom and the oil will rise to the top.

Now tip the bottle back and forth and make some waves.

The waves will be bigger at one end of the bottle and smaller at the other.

Why?

Your bottle wave is like an ocean wave.

Water moves up and down and doesn't go forward as the wave goes through the water.

The friction between water and wind makes a wave.

Longer waves travel faster than shorter ones and go further before friction makes them disappear.

From kidspot

Riddles

Lets do this riddles...

See how well you know about animals... click on the link below

Riddles

CUCUK SAYA – AIR TIDAK AKAN KELUAR

(‘Stab me – the water doesn’t come out’) 

Bagaimana melakukannya? (‘How to do it?’) 

1. Bahan – bahan yang diperlukan (‘What Do I Need?’) 

• Beberapa pensil yang ditajamkan (‘Sharpened pencils’) 

• Beg plastik bersaiz sederhana (‘Plastic bag (medium size’) 

• Air (‘Water’) 

2. Isikan plastik beg dengan air dan ikatkan atasnya. (‘Fill a plastic bag with water and seal the top tightly.’) 

3. Cucuk satu pensil ke beg plastik. (‘Stab one pencil into the plastic bag.’) 

4. Kemudian, cucuk lagi beg plastik dengan beberapa pensil yang ditajamkan, air tidak akan keluar dari beg plastik walaupun setitik. (‘Puncture the bag with several newly sharpened pencils, the water won’t leak out, never a drop.’)

Bagaimana ia berlaku? (‘How this works?’) 
1. Plastik adalah sejenis polimer sintetik. Ia diperbuat melalui proses polimerasi dan bahan asalnya ialah (etilena – sejenis gas) yang terhasil daripada petroleum. Ia sangat murah dan digunakan dalam aplikasi kehidupan seharian. (‘Plastic is a form of synthetic polymer. It is made through the polymerisation process, and its raw material (ethylene-a type of gas) comes from petroleum. It is tough yet cheap and widely used in everyday applications.’) 

2. Kebanyakan beg plastik diperbuat daripada polietilena. Apabila polietilena ini dipanaskan, molekul – molekulnya yang mengecut, jadi apabila anda mencucuk pensil menembusi beg polietilena, geseran antara pensil dan plastik memanaskan molekul polietilena dan menyebabkan molekul – molekulnya mengecut mengelilingi pensil. Itu merupakan satu sebab mengapa air tidak bocor keluar. (‘Most plastic bags are made of polyethylene. When polyethylene is heated, its molecules shrink, so when you stab a pencil through the polyethylene bag, the friction of the pencil against the plastic heats the polyethylene molecules and causes them to shrink around the pencil. That’s one reason why no water will leak out.’)

Kemahiran Proses Sains

Kemahiran Proses Sains

PEMELIHARAAN HUTAN (SAINS THN 6)

Tumbuhan dan haiwan merupakan unsur penting dalam kehidupan manusia kerana ianya dapat membekalkan sumber makanan dan bahan mentah. Pemeliharaan dan pemuliharaan dapat mengekalkan keseimbangan ekosistem di mana kita meminimumkan pemusnahan habitat haiwan dan juga mengelakkan daripada berlakunya pencemaran.

Hutan lipur adalah antara satu kaedah yang digunakan untuk memelihara flora dan fauna yang ada di sekeliling. Hutan lipur Ulu Kenas di Kuala Kangsar adalah contoh hutan lipur yang dijaga untuk mengekalkan kehijauan hutan dan juga untuk mengekalkan spesis flora agar tidak pupus. Terdapat banyak spesis tumbuhan di sini. Ianya juga dijadikan sebagai tempat rekreasi dan terdapat juga tempat untuk melaksanakan kursus ataupun kem motivasi.

                                    

Tapak perkhemahan di Hutan Lipur Ulu Kenas

               


pelbagai spesis flora                             

pokok pisang hutan

                                               

spesis palma jenis kipas                                      

                                                                               
Berbagai aktiviti boleh dilakukan di sini seperti berkhemah dan juga sebagai tempat untuk mengendalikan pelbagai jenis kursus. Kehijauan hutan lipur ini harus dikekalkan sebagai salah satu tempat untuk beriadah dan berehat setelah penat bekerja. Para pengunjung diminta menjaga kelestarian hutan ini demi mengekalkan khazanah yang tiada tolok bandingnya.Cintailah hutan kita!   

Dipetik dari Laman Blog Guru Sains

SISTEM RESPIRASI HAIWAN (SAINS THN 4)

Haiwan mempunyai organ respirasi yang pelbagai. Antara organ respirasi haiwan adalah:-

1. paru-paru
2. kulit lembab
3. insang
4.struktur trakea
5. buku paru-paru

Berikut ialah imej bagi beberapa jenis organ respirasi haiwan.

Amfibian menggunakan paru-paru dan kulit lembap.

Dipetik dari laman Blog Cikgu Sains