Q&A - P3 Science

[atutor2001]

Nebbermind:

Need advice on magnetic prop of Stainless Steel.


From what I was told, different grades of S/Steel will have different magnetic prop. So what is taught in schools, or rather what is the accepted 'answer' for PSLE?

Wow! you have brought out a very scary exception to the property of steel.

To-date, I have not come across any question on magnetic property of stainless steel. So far, Pr Science has limited the list of magnetic material to iron, steel, cobalt, nickel and carbon. Lets pray that no adventurous teacher will bring in \"stainless steel\" for question on magnetism. Otherwise, it will bring more confusion, similar to question like whether \"does shark lay eggs or give birth to young alive\" - students who read science journals will know that the answer is \"not possible to tell\", depending on the species. So the answer on magnetic property of stainless steel will again be \"not possible to tell\", depending on the grade of the stainless steel.

[Nebbermind]

atutor2001:

Wow! you have brought out a very scary exception to the property of steel.


To-date, I have not come across any question on magnetic property of stainless steel. So far, Pr Science has limited the list of magnetic material to iron, steel, cobalt, nickel and carbon. Lets pray that no adventurous teacher will bring in \"stainless steel\" for question on magnetism. Otherwise, it will bring more confusion, similar to question like whether \"does shark lay eggs or give birth to young alive\" - students who read science journals will know that the answer is \"not possible to tell\", depending on the species. So the answer on magnetic property of stainless steel will again be \"not possible to tell\", depending on the grade of the stainless steel.

Just came across in some worksheet. Think it's a qn on separating diff metals using magnet and S/Steel is classified as 'magnetic'.

[atutor2001]

Nebbermind:

atutor2001:

Wow! you have brought out a very scary exception to the property of steel.


To-date, I have not come across any question on magnetic property of stainless steel. So far, Pr Science has limited the list of magnetic material to iron, steel, cobalt, nickel and carbon. Lets pray that no adventurous teacher will bring in \"stainless steel\" for question on magnetism. Otherwise, it will bring more confusion, similar to question like whether \"does shark lay eggs or give birth to young alive\" - students who read science journals will know that the answer is \"not possible to tell\", depending on the species. So the answer on magnetic property of stainless steel will again be \"not possible to tell\", depending on the grade of the stainless steel.

Just came across in some worksheet. Think it's a qn on separating diff metals using magnet and S/Steel is classified as 'magnetic'.

Oh dear! A new evil has been created. The \"shark\" question was around some 10 over years ago. There was no \"stainless steel magnetism\" problem then. Hope that this worksheet is not a past year school question but just a question from assessment books. Otherwise I really wish that MOE has a permanent rep. in this forum to address all these \"not possible to tell\" issue.

PS
Just remembered one more nightmare which often surfaces in school paper. The question is \"Is pollen grain single cell.\" I was surprised to find the schools' answer to be yes. Actually pollen grain has at least 2 cells. Otherwise how to grow pollen tube and then fertilise the ovum.

[Just4Fun]

Q fr Lower Block Science by Janet Sim :

Which of the following statesments about our teethn are true ?
a, Our teeth cut and grind the food we eat into simple substances that can be absorbed by our body .
b, Our teeth produce digestive juices to break down food
c, we hv a max of 32 permanent teeth
d, we hv 2 sets of teeth in our life.

Ans is C & d only.

Why (a) is not true ? Anyone can help to explain ?
Thx so much !

[atutor2001]

Just4Fun:

Q fr Lower Block Science by Janet Sim :

Which of the following statesments about our teethn are true ?
a, Our teeth cut and grind the food we eat into simple substances that can be absorbed by our body .
b, Our teeth produce digestive juices to break down food
c, we hv a max of 32 permanent teeth
d, we hv 2 sets of teeth in our life.

Ans is C & d only.

Why (a) is not true ? Anyone can help to explain ?
Thx so much !

(a) is not true because of the words \"simple substances\". This should be covered only in P6 under decomposition. Teeth can only cut and grind food into \"smaller pieces\". In Pr Sc, \"simple substances\" means substances that are much simpler in structure and this can only be achieved through the process called decomposition (P6).

[Just4Fun]

atutor2001:

Just4Fun:

Q fr Lower Block Science by Janet Sim :

Which of the following statesments about our teethn are true ?
a, Our teeth cut and grind the food we eat into simple substances that can be absorbed by our body .
b, Our teeth produce digestive juices to break down food
c, we hv a max of 32 permanent teeth
d, we hv 2 sets of teeth in our life.

Ans is C & d only.

Why (a) is not true ? Anyone can help to explain ?
Thx so much !

(a) is not true because of the words \"simple substances\". This should be covered only in P6 under decomposition. Teeth can only cut and grind food into \"smaller pieces\". In Pr Sc, \"simple substances\" means substances that are much simpler in structure and this can only be achieved through the process called decomposition (P6).

Thanks so much, atutor2001, for yr clear explaination.. Appreciate it very much !

[Champion]

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Q37 (a) State two differences between the rose plant and the mushroom (2m). (Do not compare shape and size)

DD1's answer: The rose plant makes its own food but the mushroom find food.

Is my DD1's answer acceptable?


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Q: The picture shows a cup. Mary's two-year-old sister uses it to drink milk. She accidentally dropped the cup. However, the cup did not break.

What material is the cup likely to be made of? (1m)
Answer Sheet:The cup is likely to be made of metal.

DD1's answer: It is likely to be plastic.
Is my DD1's answer acceptable?

[teh_oh]

Hi Champion,


Mushroom does not ‘find’ food. They feed on other organisms dead or alive.
So my answer will be,
The rose plant makes its own food while the mushroom does not make its own food. It feeds on other organism dead or alive.

For the second question, I will accept Plastic too.

Now hoping others can confirm.

[teh_oh]

Hi Parents,


Below is a question from Conquer Science Exercise 29 - Exploring Materials.

1. Nylon is a man-made material that is usually used for making clothes.
b. Clothes that are made of nylon are more water-resistant than clothes made of cotton. Why is it so?

Answer Key: Nylon is a plastic, which makes it water-resistant.

My query:
Nylon is a plastic? I thought it is a man-made fibre/fabric.
Is there a clearer answer than the above?

Thank you.

[Andaiz]

Champion:

Q37 (a) State two differences between the rose plant and the mushroom (2m). (Do not compare shape and size)

DD1's answer: The rose plant makes its own food but the mushroom find food.

Is my DD1's answer acceptable?

Champion, the instruction says \"Study the following pictures carefully\", so whilst your DD1's answer is acceptable, it is INFERENCE, not OBSERVATION.

Chances are the teacher could be looking for answers like \"The rose plant has leaves whereas the mushroom does not.\"

:shock: :yikes: I also feel the same way, that's its too robotic a kind of answer but at a P3 Subject Briefing, the HOD actually advised such for lower science block :slapshead:

Champion:

Q: The picture shows a cup. Mary's two-year-old sister uses it to drink milk. She accidentally dropped the cup. However, the cup did not break.

What material is the cup likely to be made of? (1m)
Answer Sheet:The cup is likely to be made of metal.

DD1's answer: It is likely to be plastic.
Is my DD1's answer acceptable?

It should be, point is it is unbreakable. Hope that helps!