NYPS Calendar 2010

Monday, May 31, 2010

Monday, May 10, 2010

Matter

Matter

A substance that has mass and occupies space is classified as matter.

Substances that have no mass and do not occupy space are classified as non-matter.

Unit of measurement of mass = kg or g
Unit of measurement of volume = ml or L

Matter exists in three main states:

- solid
- liquid
- gas

The properties of each state are as follows:

Solid

1. Fixed shape - will not change by itself
e.g. Plasticine is a solid. Its shape will not change unless we do something (like squeezing) to it.

Note: When we apply a force onto an object, we can change its shape (e.g. Plasticine or Blu-tack). When we say fixed shape, we mean that it does not change its shape by itself.

2. Fixed volume
e.g. If a rock has a volume of 34ml in beaker A, its volume when placed in beaker B (or anywhere else) will also be 34ml

3. Cannot be compressed
Since the volume is always the same, thus we can say that solids cannot be compressed.


Liquid

1. No fixed shape - changes according to type of container
Liquids will change their shape according to the container they are in. Square container = square shape. Triangular container = triangular shape

2. Fixed volume
e.g. If beaker A contains 12ml of water, the volume of water when it is poured into another beaker is still 12ml.

3. Cannot be compressed
Since the volume is always the same, thus we can say that liquids cannot be compressed.


Gas

1. No fixed shape - changes according to type of container
Gases are like liquids and will change their shape according to the container they are in. Square container = square shape. Triangular container = triangular shape

2. No fixed volume
e.g. If 10ml of gas is pumped into a 5ml container, the volume of the gas will be 5ml.
If the same 10ml is pumped into a 20ml container, the volume of the gas will be 20ml.

KEY CONCEPT: Gases compresses or expands in order to fill up the container that it is in.

3. Can be compressed and can expand
Please see the above point.

Good luck for tomorrow!

Sincerely,

Mr. Chan

Thursday, May 6, 2010

Moulting

Dear All,

Upon request:

http://en.wikipedia.org/wiki/Moulting

http://www.insectidentification.org/process-of-molting.asp

As moulting literally means to lose part of its body, the pupa moults (loses its outer protective covering) to become an adult.

Thank you!

Sincerely,

Mr. Chan