CHAPTER 8 : The World Through Our Senses

Hi Teens ! You're now welcome to Chapter 8 : The World Through Our Senses. This chapter will discuss about 
- Human sensory organs ( eye, tongue,ear,nose,skin)
- Sight defect
- Response by plants


I will explain to you each of these subtopic so don't you have worry. Okay!

Concept Of Mass

Mostly, students always confused in the concept of mass and weight. Am I right? yeah! I knew it. 

Now, I'll explain to you one by one.


Firstly,

Concept Of Weight

1. The weight of an object is - the force of the gravitational pull that acts on the object.
2. It can change,depends on the gravitational attraction that acts on the object. Because of this, the weight of an object differs from place to place.
3. The S.I unit for weight is - Newton (N)
4. Measured by using a - spring balance / compression balance.

SPRING BALANCE

Secondly,

Concept Of Mass

1. The mass of an object is - the quantity of matter that is present in the object.
2. The mass is fixed and not influenced by the force of gravitational pull.
3. The S.I unit for mass is - kilogram (kg) / gram (g) / milligram (mg).
4. Measured by using a - lever balance / electronic balance / triple beam balance.

ELECTRONIC BALANCE

LEVER BALANCE

TRIPLE BEAM BALANCE

So now, are you clear with these explanation ? If you are still can not see clearly with that concept between mass and weight. Here I show you, their differences between the concept of mass and weight.

Common Laboratory Apparatus

Okay Teens! 

Now, you will be introduce the common laboratory apparatus that used when doing scientific investigation.

Here are some common apparatus used in the laboratory.

May I introduce you.....♥

In the picture above, there are only a few common apparatus laboratory that you'll used to it.

Here I give some more apparatus in the lab.

Each of the apparatus, you have to learn and know on how to use it when you are doing the science investigation.

You don't have to worry. I will teach you more about this lab apparatus in measuring tools. Okay!

Hazard Warning Symbols

Hi Teens! For Your information, there are many hazardous substances in the science laboratory.
Here I show you,some common hazard warning symbols that warn of dangerous substances in the laboratory regarding your syllabus. 

In your syllabus, there are only six hazard symbols that you've known and you should familiar with.

• Harmful / Irritant - irritates the eyes and skin by inhalation,or if swallowed it.
• Inflammable      - can burn easily
• Corrosive          - can cause damage to skin and eyes if it comes into contact with the skin         and eyes.
• Toxic / Poisonous - can cause death or harm if it is swallowed or inhaled.Certain poisonous can be absorbed through the skin.
• Explosive               - Substances like sodium & potassium are easily to explode. Its stored under paraffin in airtight container.
• Radioactive           - Gives out radiation which can cause damage to body cells and tissue.