Showing posts with label UNIC OF SCIENCES. Show all posts
Showing posts with label UNIC OF SCIENCES. Show all posts

Tuesday, September 6, 2011

jom buat latihan

The table below shows the result of an experiment. Underline the      
correct answer.                                                                        [10 marks]
Jadual di bawah menunjukkan keputusan satu eksperimen. Garis
jawapan yang betul.                                                              [10 markah]

Spring
Original  length
Panjang asal
Length after the spring is stretched
Panjang selepas spring itu diregang
A
2 paper clips
2 klip kertas
3 paper clips
3 klip kertas
B
2 paper clips
2 klip kertas
7 paper clips
7 klip kertas
C
2 paper clips
2 klip kertas
5 paper clips
5 klip kertas


1-    A spring becomes ( shorter  /  longer ) when it stretched.
Spring menjadi   (  lebih pendek  /  lebih panjang  )  apabila diregangkan.

2-    Spring (  A  /  B  /  C  ) stretches the least.
Spring  (  A  /  B  /  C  ) meregang paling sedikit.

3-    Spring   C   is  easier to stretch than spring  (  A   /   B   ).
Spring   C  lebih mudah diregangkan daripada  spring  (  A  /  B  )

4-    The springs have different  (  lengths  /  diameters  ).
Spring-spring itu  mempunyai  (  panjang  /  diameter  ) yang berbeza.
                                                                       
5-    If two springs have the same length but different diameters, the spring with the bigger diameter will strectch  (  more  /  less  )
              Jika dua spring mempunyai panjang yang sama
              tetapi  diameter yang berbaza, spring dengan diameter yang
              lebih besar akan meregang  (  lebih banyak  /  kurang  ).

unit 8- MIXING SUBSTANCES

MIXTURES : When two or more substances are mixed together but not chemically joined they are called as mixtures.
Mixtures are absolutely everywhere you look. Mixtures form for most things in nature. Rocks, air, or the ocean, they are just about anything you find. They are substances held together by physical forces, not chemical. This statement means that the individual molecules enjoy being near each other, but their fundamental chemical structure does not change when they enter the mixture.
The methods of separation of mixtures depend on the constituents of the mixtures.
The constituents in a mixture can be separated by easy methods like picking, sieving, or winnowing. You can make a mixture of rice, paper, clips and marbles. These can be separated into different piles of rice, paper, clips and marbles. Some mixtures can be separated by evaporation or condensation.

Solutions : Have you ever put sugar in a glass of milk? After you stir, you can no longer see the sugar. The sugar is still there, as you can taste it. A mixture of sugar and milk is called as solution. By evaporation we can separate the different kinds of matter in solution.


Physical changes: Matter undergoes changes. Changes in matter, in which no new substances are formed are called as physical changes. Changes in temperature can make matter look different. Cooling makes liquid water change to ice.
Physical changes of matter
The ice has the same particles, the liquid water has. It can be reverted back to water by melting. Here no new substances are formed. So it is a physical change.
Chemical changes : Matter undergoes changes. Some changes produce new substances. Such changes are called as chemical changes. When wood burns, it combines with the oxygen in air and forms smoke and ash.
Chemical changes of matter - fire         Chemical changes of matter - burning
You notice an orange brown coating on things made of iron when they come in contact with moisture. This is called as rust. Rusting is a chemical change.
Chemical changes of matter - rust