CHEMISTRY BLOG :D

Friday 8 July 2011 @05:35

-3E5 -

@05:30

ME AND VERENA !! :D

@05:06

Trip to Vietnam :D

@04:11

Aleen (27)

From her answers, i could see that she really did put effort and it is really detailed. The pictures were big and clear for us to see. However, for Question 2, her drawing for sodium ion's charges was wrong. It should be '+' and not '1+'.

ShuYu (12)

The answers provided by Shuyu is very detailed and clear. She even provided picture for us to understand better and she changed her words colour to bright colour for us to read clearly. I think that she could write the maximum number for each shell like what she did in Question 2 and 3 for Question 1.

Wanling (16)

Her answers were short but straight to the point. I can see that she put effort in her wok and searching for pictures. But i hoped that she would be more detail and her sulfur ion does not the bracket and charges.

Sunday 3 July 2011 @22:26

-END OF ASSIGNMENT-

( for missing questions please press july 2011 at the archives section)

@21:59

Besides referring to the periodic table to know that sodium is a metal and sulfur is a non-metal as the elements in Group (I), (II) and (III) of the periodic table is metal and Group (IV),(V),(VI) and (VII) of the periodic table is non-metal. We could also refer to the number of electrons of the element.

Sodium (2.8.1) is a metal because it will lose 1 electron to complete the valence shell( to make it stable) and conduct electricity. Sulfur(2.8.6) is a non-metal because it will gain 2 electrons to complete the valence shell (to make it stable) and it does not conduct electricity.

Additional: Group (III) is also known as transition metal or coloured metals. Group (0) is known as the noble gas as they can stabilise themselves.

@21:45

From the picture, we can see that they have the same number of protons. (17 protons). However, chlorine-35 has 18 neutrons while chlorine-37 have 20 neutrons. Thereofore, they are isotopes as the definition of isotopes is " Different atoms of the same element which have the same number of protons but different number of neutrons".

@21:31

Sulfur atom needs 2 more electrons in the outermost shell to stablize. Thus, sulfide ion will be negatively charged. The number of protons did not change but the number of electron increase by 2. . The first shell can only have two electron maximum and 4 pairs of electron for the second and third shell.

@21:25

It has 16 electrons. The outermost shell have only 6 electrons because the first and second shell is full. . The first shell can only have two electron maximum and 4 pairs of electron for the second and third shell.

@21:23

Sodium loses an electron and becomes positively charged. The number of protons in sodium did not change but the number of electron will decrease by one. After losing an electron, sodium will be stabilize. It has eleven electrons. The outermost shell have only 1 electron is because the first and second shell is full. The first shell can only have two electron maximum and 4 pairs of electron for the second and third shell.

@21:04

It has eleven electrons. The outermost shell have only 1 electron is because the first and second shell is full. The first shell can only have two electron maximum and 4 pair of electron for the second and third shell.

@19:01

The atom is the smallest foundation unit or particle of an element that an exist.

1.All atom of the same element are alike. They all have particles concentrated in the centre called the nucleus. The nucleus consists of two types of particles, namely proton and neutron. The protons are positively charge while the neutrons do not have charge. Both of them have the same mass. Surrounding the nucleus are electrons which are negatively charged. The relative mass of electron is 1/1840.

The electrons circulate the nucleus in some fixed pattern. The first two electrons nearest to the nucleus circulate in an elliptical path. These two electrons are constantly in motion in the fixed path. This path is known as the first electron shell and can hold at most two electrons. Any other electron will have to go on to the second shell. The second shell can hold at most 4 pairs of electrons which are constantly circulating in pairs. Once the second shell is full with 8 electrons, the electrons move to the third shell which can also hold at most 8 shells. The number of protons in the nucleus is the atomic number. For an atom, the number of protons is equal to the number of electrons. The number of neutrons plus protons in the nucleus is known is the nucleon number.

Saturday 2 July 2011 @09:23

Atomic Structure Assignment

Hello all, I have explained the concepts of an atomic structure in my last few lessons. I am quite sure you are keen to share your understanding with all the bloggers and me....write as much as you can about it...., I will be very impressed!! Please enjoy completing the assignments below :

1. What does an atom looks like? What are the sub-atomic particles inside it.....(talk about electrons, neutrons, protons, electron shells, nucleus....)

2. Draw the atomic structure of a sodium atom and a sodium ion....explain why you draw it this way.

3. Draw the atomic structure of a sulfur atom and a sulfide ion....explain why you draw it this way.

4. Chlorine-35 atom and Chlorine-37 atom are called isotopes...Use these two examples to explain what is 'isotopes'.

5. Sodium is a metal and sulfur is a non-metal....why we classify them this way??