All right, enough with math and chem. It's time for the most torturous subject ever, PHYSICS! BWAHAHAHahahahaaa...... ... ._.

Try plunging the world into a duck's gutter, "scatter-brains" is what you get :) (Don’t question me why I just have to use Duck of all living thingys out there)

"The poet only asks to get his head into the heavens. It is the logician who seeks to get the heavens into his head. And it is his head that splits."
─G.K Chesterson
let's start off with

MASS

It is a measure of the amount of matter in objects

- The magnitude of the mass of a body depends on the size and the number of atoms

-Mass is a basic property of matter

-An object will have a fixed mass regardless of its location, speed or shape of the object (so girls, next time when you wanna compare weight, say MASS)

SI unit of mass is kilogram (Kg)

-Mass is scalar quantity

Mass can be measured by sliding mass balance and elctronic balance (more accurate and easier to use)

Inertia (i don't think you need to know this..) someone enlighten me.

-It is defined as the reluctance of a body to start moving on its reluctance to stop once it is in motion

-The larger the mass of a body, the greater its inertia

Gravitational field strength

It is defined as the gravitational force acting on per unit mass of an object

-On earth, the gravitational field strenght is 10N Kg-1

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Symmetry and angle properties of polygons

a polygon is a plane figure with 3 or more straight edges as its sides (in other words, no circles. or weird blobs).

REGULAR POLYGONS:
the basics are as such: no. of sides = what polygon
i) 3 = equilateral triangle
ii) 4 = square
iii) 5 = pentagon
iv) 6 = hexagon
v) 7 = heptagon
vi) 8 = octagon
vii) 9 = nonagon
viii) 10 = decagon

(you'll realise that the front portion of the name can come out in chemisty too. like pentane. *coughs* but i'm talkin' math here, buddy. )

the formulaes are:
i) sum of interior (int.) angles (ang) of an n-sided polygon = (n - 2) x 180* (* = degrees)

eg: sum of int.ang of a triange = (3-2) x 180*
which is like duh since sum of all int.angs in a triangle = 180*

or eg. sum or int.ang of a nonagon = (9-2) x 180* = 1260*
(don't believe me? go draw, and figure why it's 1260*. this can apply to irregular polygons, so there's hope yet. yay. *deadpans* )


ii) sum of exterior(ext.)angs of an n-sided polygon = 360*
(if you don't know, go draw one and measure. mathematicians must have figured that since there is NO change no matter how many times they draw it, it just has to be like that. hence the formulae. note: it doesn't say regular polygon either. )


iii) each int.ang of a regular n-sided polygon = [(n-2) x 180*]/n
sorry, it's in fractions. the / = divided by.

eg: 1 int of a nonagon= [(9-2) x 1980*]/9 = 1260*/9 = 140*


iv) each ext.ang of an regular n-sided polygon = 360*/n

eg: ext.ang nonagon = 360*/9 = 40*


v) no of sides of a regular polygon = 360*/ (1 ext. ang)
eg: no. of sides of a regular polygon= 360*/40* = 9 sides = nonagon
(see? see?)


vi) 1 ext.ang + 1 int.ang = 180*
(aka angs on a stright line. but that's in another angles chapter.)

(If you don't believe it, go draw. then you get your ans. it's always like that, like how the sun rises from the east and sets in the west. not north. or south. and we won't have an icy atlantica and instead might get an icy singapore. if you still don't get it, too bad. )

Covalent bonding
This is pretty risky--I know what are covalent bonds. But i don't exactly know how to explain them. So all the best to me and you who may be confused after reading this.

• Covalent bonding is the sharing of electrons.
  
• It is a bond between non-metals and non-metals. Metals!! SIAM!!!
  
  
• Okay. Here's my shot at it. We know the Chlorine has 7 electrons in its outermost shell and needs one more electron to fulfil the octet configuration. Right? Say yes.
  therefore the electronic configuration looks like this:
  

If you want the two chlorines to bond together, they can't by ionic bonding because both have a negative charge and will never have no charge when they are bonded ionically. Do i make sense? i think i do.

therefore they share electrons instead. How ar? how? In the case of Chlorine, they share ONE pair of electrons. Like that both also got 8 electrons on the outer shell.

When they share, when counting the number of electrons in the outermost shell, you MUST include the one shared, meaning the one the other atom nice nice share with you. if not share for what. aiyo.
So it looks like this:

The shared ones is the one in the middle. It's just like when a couple get married they start to share room, share spoon(y), fork, towel, soap, house, and of course, bed! hoho. p/s: You DO know marriage is a kind of bond right? please say yes.

• I forgot one thing. The electrons at the outermost shell is called the valence electrons.
• You all want to try how CO2 bonds? I don't care. Say yes. It's kind of math. So must practise. I don't care. die die also must practise. if not you die not my fault.

Co2 de bond will look like this:


Wah...you see carbon got 2 wives leh. see the price to pay for having an affair? Must handle more things. Must be more devoted like Cl2 lar!

You all got basic idea? I hope la hor. I try my best liao. I know the drawing sucks but you can't blame paint. It's a poor thing program already.

Properties of Covalent Bonds

• Volability (how well they evaporate): This one must depend on the molecular structures. The stronger the molecular structures, the higher the boiling point. I'll explain molecular structures in the next post. dying already. Who? Me la.
  
  
• Solubility: Mostly insoluble in water, but hor, got some super extra ones want to make us study more so they can be soluble. Eg. Sugar and alcohol. Then those with simple molecular structures normally dissolve in organic solvents. You only need to know organic solvents by name. tell you what they are not only you die, i also die with you.
  
  
• Electrical conductivity: For electicity to travel, must have free electrons flying around so there's ions. But covalent bonding, you also know, share with so many concubines also don't have any flying around liao, so can't conduct electricity. HOWEVER, sway sway hor, graphite, allotrope of carbon also want to be extra then can conduct electricity leh! I tomorrow then explain what is allotrope. Today brain cannot absorb too much. because it's friday night. THEN HOR, got other extra ones leh. Hydrogen Chloride and hydrogen sulphide can conduct electricity when dissolved in water. sway sway. memorise lor. bo bian
  
  
  Nothing more to say liao. Tomorrow then flood you all. Talk more i also no brain already. BYE!!!
  

Ionic Bonding

Now you know how to identify the charges, we shall talk about ionic bonding. Ionic bonding is the bonding of Metals and Non-metals via the giving and taking of electrons.

Let's start off with something simple.
eg.
Potassium has a 1 electron in its outermost shell as it is in group I of the periodic table. and needs to give away one electron to fulfil the octet configuration. Thus it has a charge of (+1).
Iodine has 7 electrons in its outermost shall as it is in group VII of the periodic table and needs to take in one more electron to fulfil the octet configuration. Thus it has a charge of (-1).
When ionic bonding occurs, the main purpose is to make the positive and negative charge equal so. Thus, to make the charges of the two elements equal, we need one of each element.

Therefore, Potassium and Iodine will react to form KI, potassium iodide by ionic bonding.

Calcium + Chlorine?

Calcium has a charge of 2+
Chlorine has a charge of 1-

How to balance? To make the negative charge = positive, we need two chlorine atoms right? bingo.

So it forms CaCl*2, calcium chloride

* represents subscript

Got it? Yay. xD

try others.
Magnesium + Oxygen? ans: MgO
Aluminium + Oxygen? ans: Al*2O*3
Sodium + Chloride? ans: NaCl
Calcium + Chloride? ans: CaCl*2
Zinc (II) + Oxygen? ans: ZnO
Iron (III) + Oxygen? ans: Fe*2O*3
Silicon (IV) + Oxygen? ans: SiO*2

Chemistry- Atomic structure and chemical bonding

• An atom consists of three particles.
  
  1. Proton (Positive charge)
     
  2. Neutron (no charge)<>
  3. <>Electron (Negative charge)
     
     
• Proton number=electron number
  
  
• Up to this stage, we only need to care about electrons. The other two can sua.
  
  
• Electrons are arranged in energy shells. The first shell can take 2 electrons, second can take 8 and the third can take 8 as well. Sulphur can take 10 in it's third shell. Extra la. The shells more than these, we don't need to know yet. I also don't know.
  
  Below is an example of how the shell thing, called the electronic configuration is drawn. This is the electronic configuration of sulphur, S.
  
  Sulphur has 16electrons. What matters is not the electrons of the first and second shell, but the other most shell. The others also can sua. As you can see, there are 6 electrons in the outermost shell and therefore sulphur is in Group VI of the periodic table. The groups of the periodic table tells you the number of electrons each element has in their outer most shell. The elements without a group are called transition metals. You don't need to know what they are. They'll kill you.
  

• The third shell requires 8 electrons for it to be full right? The sulphur only has 6 electrons at the outermost shell right? Then it needs two more electrons. Since each electron has a charge of (-1) and sulphur needs 2 more electrons to obtain the octet configuration, sulphur has a charge of (-2) and is presented in this way: S^(-2)
  
  
• However, for elements such as Sodium, which has one electron in its outermost shell, will have a charge of (+1) instead. you compare ar, having to give away one electron and having to steal 7 others. giving away one is easier right? So the elements in group I to IV have positive charges instead. they give away the negative one, so it's in mathematical terms, (-)(-1)=+1. So its positive.
  
  
• But something to take note of is some elements in group III and IV may be transition metals too. This one don't worry. It's gonna be indicated by the names of the elements. For example, Lead is in group IV, but it may have different charges. Lead(IV) may have a charge of (+4), but Lead(II) has a charge of (2+). How to determine? By their names.
  
  
• Group 0 elements are unreactive because they have already filled their outermost shells. Thus they have no charge.