Q&A - P3 Science

[mother777]

smartmummy:

Super.kiasu:

Do your have any questions? I am quite good at science. If I can't answer I will google it.

Thanks for willing to help.Appreciates

I have a qn. This is not from P3 syllabus. We like to do experiments at home.Today we put egg (tooking from room temprature) in the tap water it sinked.Then we took an egg from freezer and put in the same water.It floated.What could be the reason?

Hi Smartmummy,

this is the explanation i found online when i searched for sinking or floating of eggs.

\"A very fresh egg will immediately sink to the bottom and lie flat on its side. This is because the air cell within the egg is very small. The egg should also feel quite heavy.

As the egg starts to lose its freshness and more air enters the egg, it will begin to float and stand upright. The smaller end will lie on the bottom of the bowl, whilst the broader end will point towards the surface. The egg will still be good enough to consume, however, if the egg fully floats in the water and does not touch the bottom of the bowl at all, it should be discarded, as it will most likely be bad. \"

[atutor2001]

mother777:

Hi Smartmummy,

this is the explanation i found online when i searched for sinking or floating of eggs.

\"A very fresh egg will immediately sink to the bottom and lie flat on its side. This is because the air cell within the egg is very small. The egg should also feel quite heavy.

As the egg starts to lose its freshness and more air enters the egg, it will begin to float and stand upright. The smaller end will lie on the bottom of the bowl, whilst the broader end will point towards the surface. The egg will still be good enough to consume, however, if the egg fully floats in the water and does not touch the bottom of the bowl at all, it should be discarded, as it will most likely be bad. \"

Just a little elaboration on how more air can enter the egg and how it is link to putting egg in the refrigerator.

There is water in the contents of an egg. Overtime, some of the water in the egg will evaporate. Air will then enter to take its place. Therefore, the weight (or density) of the egg will decrease and will finally be able to float.

Now on the effect of placing egg in a refrigerator. The humidity (amount of water vapour) of the air in a refrigerator is very much lower than outside air because when the air inside the fridge is cooled, the water vapour will condense. (long time ago, there is a tray in every refrigerator to collect condensate) As we know, when the humidity is low, the rate of evaporation will increase. Therefore, the rate of evaporate of the water in an egg kept in a refrigerator will be faster than another one left in the open. This explains why egg will be able to float if you keep it in a refrigerator.

[smartmummy]

mother777:

smartmummy:

[quote=\"Super.kiasu\"]Do your have any questions? I am quite good at science. If I can't answer I will google it.

Thanks for willing to help.Appreciates

I have a qn. This is not from P3 syllabus. We like to do experiments at home.Today we put egg (tooking from room temprature) in the tap water it sinked.Then we took an egg from freezer and put in the same water.It floated.What could be the reason?

Hi Smartmummy,

this is the explanation i found online when i searched for sinking or floating of eggs.

\"A very fresh egg will immediately sink to the bottom and lie flat on its side. This is because the air cell within the egg is very small. The egg should also feel quite heavy.

As the egg starts to lose its freshness and more air enters the egg, it will begin to float and stand upright. The smaller end will lie on the bottom of the bowl, whilst the broader end will point towards the surface. The egg will still be good enough to consume, however, if the egg fully floats in the water and does not touch the bottom of the bowl at all, it should be discarded, as it will most likely be bad. \"[/quote]I also found this.Thanks.

[smartmummy]

atutor2001:

mother777:

Hi Smartmummy,

this is the explanation i found online when i searched for sinking or floating of eggs.

\"A very fresh egg will immediately sink to the bottom and lie flat on its side. This is because the air cell within the egg is very small. The egg should also feel quite heavy.

As the egg starts to lose its freshness and more air enters the egg, it will begin to float and stand upright. The smaller end will lie on the bottom of the bowl, whilst the broader end will point towards the surface. The egg will still be good enough to consume, however, if the egg fully floats in the water and does not touch the bottom of the bowl at all, it should be discarded, as it will most likely be bad. \"

Just a little elaboration on how more air can enter the egg and how it is link to putting egg in the refrigerator.

There is water in the contents of an egg. Overtime, some of the water in the egg will evaporate. Air will then enter to take its place. Therefore, the weight (or density) of the egg will decrease and will finally be able to float.

Now on the effect of placing egg in a refrigerator. The humidity (amount of water vapour) of the air in a refrigerator is very much lower than outside air because when the air inside the fridge is cooled, the water vapour will condense. (long time ago, there is a tray in every refrigerator to collect condensate) As we know, when the humidity is low, the rate of evaporation will increase. Therefore, the rate of evaporate of the water in an egg kept in a refrigerator will be faster than another one left in the open. This explains why egg will be able to float if you keep it in a refrigerator.

:goodpost: :thankyou: atutor2001! appreciate

[Nebbermind]

smartmummy:

I have a qn. This is not from P3 syllabus. We like to do experiments at home.Today we put egg (tooking from room temprature) in the tap water it sinked.Then we took an egg from freezer and put in the same water.It floated.What could be the reason?

interesting! I've never placed an egg inside the freezer before!!

[SAHM_TAN]

smartmummy:

I have a qn. This is not from P3 syllabus. We like to do experiments at home.Today we put egg (tooking from room temprature) in the tap water it sinked.Then we took an egg from freezer and put in the same water.It floated.What could be the reason?

[/quote]

From the freezer... Did you crack open the egg to check if it's frozen?

[smartmummy]

SAHM_TAN:

smartmummy:

I have a qn. This is not from P3 syllabus. We like to do experiments at home.Today we put egg (tooking from room temprature) in the tap water it sinked.Then we took an egg from freezer and put in the same water.It floated.What could be the reason?

From the freezer... Did you crack open the egg to check if it's frozen?[/quote]
I wanted to check then I forgot to check.

We always filled up water in a different shapes of recycle containers.After that took out the ice and looked the different shape of ice.One day i put that egg and wanted to see how it freeze and can show to kids.
In another day we check the egg sink or float in the tap water then in the salty water.Then I remembered that egg i put in the freezer.Then I checked.But I forgot to crack.I did this during cooking.So i throw everything and continued my cook.I will do in another time.

[smartmummy]

My son grows green bean plant.Its well up to young plant,then it dead.He put 4 seedlings in a small pot and pour water every day.Put outside so can get sunlight.After new leaves came it dead.What could be the reason?

I thought the root didn’t get air so I just dig(not deep) around the plant.Still no use, now only one plant alive but not healthy.Is that need big pot to get more air?

[mother777]

smartmummy,


I suspect, too much water.

too much water will cause the root to rot and the plant will die. since singapore is quite humid, too much watering is not required.

you can try watering on alternate days and see if the plant looks more healthy.

its good to know that your son is keen to do science experiments at home.

[smartmummy]

mother777:

smartmummy,


I suspect, too much water.

too much water will cause the root to rot and the plant will die. since singapore is quite humid, too much watering is not required.

you can try watering on alternate days and see if the plant looks more healthy.

its good to know that your son is keen to do science experiments at home.

Yup I thought of that then I alternate days pour the water after the leaves started to rot.Yup, he likes to do experiments.Thanks for ur input.