Form 4: Subatomic particles - The basics

Hey Form 4, this video is about subatomic particles; protons, neutrons and electrons. Watch this first:

Key points:
1. Protons carry positive charge (+ve).
2. Electrons carry negative charge (-ve).
3. Neutrons carry no charge. There is no such thing as 'neutral charge'.
4. There are two types of 'numbers':
    a. Proton number
        - Total number of protons in an atom
    b. Nucleon number
        - Total number of protons and neutrons
    c. You don't learn 'neutron number' at Form 4. It is not part of your syllabus, so don't worry about it. If you really want to know, post your question in the shoutbox and I'll ask a friend of mine to elaborate. =)
5. Neutron and Proton makes up the nucleus of the atom. The nucleus is surrounded by the electrons.
6. Number of electrons and protons are always equal in a neutral atom (without charge; for instance, Na, Ca, O, C, etc. Example of charged atoms are Na+, Ca2+, etc)
7. When an ATOM becomes an ION, it either RECEIVES electrons (reduction) or LOSES electrons (oxidation).
    - Receives electron = Reduction. This is because the oxidation number of the ION becomes smaller when it receives electron. The oxidation number is REDUCED. Hence, reduction. The opposite is true for Oxidation.

There you go. Digest all that information. For questions, post in shoutbox. =)

Cheers,
Teacher Ben

Form 1: Earth's resources being used up

Hi Form 1, last week I gave you the worksheet about Earth's resources for you to finish at home. We discussed a little about how Earth's resources are being used up at an alarming rate and how we need to recycle and conserve Earth's natural resources. Watch this video:

Post your questions on Shoutmix Chat on the right panel of this blog.

Cheers,
Teacher Ben

Current and Voltage

Form 3, this is the video that I used for my explanation on Current and Voltage.
The thing that you need to remember is the concept of what is current and what is voltage. Of course you need to remember the formula as well.

Key points:
1. Current is the number of coulombs of charge per second.
2. The formula is C/s (Coulomb per second)
3. Current is likened to a flowing river. The larger the current, the more the volume of water is flowing down at any given time. Likewise, the larger the electric current, the larger the amount of charge flowing through a wire at any given time.

4. Voltage is the potential for work to be done.
5. Formula is J/C (Joules per Coulomb)
6. Voltage is likened to tilting a tray of water. When it is not tilted, there is no gravitational potential energy at any point. All have equal gravitational potential energy. When the tray is tilted, the tilted side gains gravitational potential energy and flows to the other side of the tray. Voltage is the same. The dry cell creates a potential difference (like tilting the tray) that enables the electron to flow from one side to the other.

Extra notes:
1. Electron in a dry cell flows from the negative terminal to the positive terminal.
2. There are two types of substances inside a dry cell that creates the potential difference. (refer the video below for more info)

All the best. Post your questions as a comment here.

Cheers,

Teacher Ben

Science Online

Hey friends,

Students of Harvest Centre! I am going to start using this blog as a tool for us to do our study online. Periodically, i'll post videos of me teaching a particular topic or notes for a particular topic. If you have any questions or feedback in regards to the lesson on any particular day, please post your comments here. I'll be glad to know what you think. =)

In addition to that, please help me out by clicking on the advertisement on the top-right of this blog if you have found this blog to be useful. It'll help me get some money lar. =)

So, looking forward to be teaching you guys and girls online from now onward. =)

Cheers,
Teacher Ben