Final post

Hey guys! It's the last post already! Just wanna keep short and simple and of course meaningful! Basically, I wanna share another ace project of mine!

Today, I will sharing about the 2 exceptions of covalent bonding! They are :

1)Aluminum Chloride

2)Beryllium Chloride

Recap...

What's covalent bonding?

-A form of chemical bonding that is characterised by the sharing of pairs of electrons and between atoms

-A stable balance of attractive and repulsive forces between atoms when they share electrons

In covalent bonding, the general rule is that the bonds are formed between 2 non-metals.

HOWEVER, there are 2 exceptions :

1)Aluminum chloride

2)Beryllium Chloride

Note: Both are covalent bond theoretically, but they should be ionic bond.

Lets start with aluminum chloride :

Made up of : 1 Aluminum atoms

3 chlorine atoms

So, Why aluminum chloride a covalent bond?!

1)Due to Polarization.

2) Cations are very polarizing, while anions are very polarizable.

3) The higher the charge of the cation will increase, the degree of the distortion of electron cloud surrounding the anion.

4) This shows that aluminum chloride has a considerable degree of covalent character, hence, the electron pair will be shared among the atoms.

5)The difference between the calculated and the experimental value of the lattice energy will be very high as aluminum ion a charge of 3+.

6) Besides, the atomic radius of chlorine atom is very small.

Here are some of the uses of Aluminum Chloride:

1)paint manufacturing

2) antiperspirant

3) petrol refining

4)production of synthetic rubber

5)making detergents

Next, Beryllium chloride. Made up of :

1) 1 Beryllium atom

2) 2 chlorine atoms

So why is a covalent bond too!?

1) The Be2+ cation is smaller in size and hence has high charge density.

2)This enables it to easily polarise the comparatively larger Cl- anion, which results in a covalent characteristic of the compound.

Uses of Beryllium chloride :

1)refining Beryllium ores

2)chemical reagent

So, that's all! Hope you have enjoyed and learnt many things through this platform! Thanks for your support! Enjoy! God bless all of you guys!(:

Term 3 results

Hey guys! Welcome back! Today I will be sharing and reflecting on my term 3 test results!

Alright, this term, the topics were much easier than the previous term!( in my opinion ) The topics are lights and colours of light!

Alright, I got b3 this term! But I am really disappointed.

Before the test, I studied but I became over-confident and complacent and thus I did not study very hard. I thought that since I can do well in the previous term, and so I can also do well in this term! I just read through the notes, read through my worksheets and that's all. All my classmates were studying very hard but I thought it was not necessary.

On the day of test, when I saw the questions, I wasn't sure which was the correct answers! I panicked, and hoped for the best. After the test, everybody said it was super easy but I kept quiet.

On the day I got back my test, I felt disappointed. Everybody had gotten a A1 and I got a B3! When I looked at my mistakes, I realized that actually I still did not get my facts right! From this test, I have such a big lesson in my life!

Guys, let me share what I have learnt from this experience. And I believe that what I have learnt can be applied not only in grades but also in life! NEVER BE OVER-CONFIDENT AND NEVER GET COMPLACENT! Always stay humble. Always be humble whenever you study, humble in whatever you do. Being humble can allow you to achieve great things not only in grades, but also in life! Being humble means being modest! I sincerely hope you guys can also learnt something from my experience.

Before I end of, I would like to share a bible verse. Matthew 23:12 : " For those exalts himself will be humbled, and for those humbles himself will be exalted." Guys, STAY HUMBLE IN WHATEVER YOU DO!!:D ENJOY!(:

Make Super Cool Water!

Hey guys! Well, I had done a ace project on super cooling! It's a really cool and interesting and fun project! And so I really want to share with you guys! Enjoy!!

Before I start... I would like you guys to watch this video above!

So what's going on??

-Basically, the water turned into ice almost instantly!

How to do this experiment?? (It's very simple!)

1)Get an unopened bottle of water, most preferably purified or distilled water.

2) Put the bottle of water into a freezer( set freezer to -19 degrees Celsius.

3)Wait for 2 hours and gently take out the bottle.

4)If water in the bottle freezes, it means the experiment failed thus repeat.

5)Drop a piece of ice in a bowl and pour the water onto the ice, watch what happens.

After watching the video and trying out the experiment, I believe you guys want to understand what's the theory behind all this!

Basically...

-Super-cooling, also known as under-cooling, is the process of lowering the temperature of a liquid or a gas below its freezing point without it becoming a solid.

-A liquid below its standard freezing point will crystallize in the presence of a seed crystal or nucleus around which a crystal structure can form.

-However, lacking any such nucleus, the liquid phase can be maintained all the way down to the temperature at which crystal homogeneous nucleation occurs.

-The homogeneous nucleation can occur above the glass transition where the system is anamorphous solid.

Actually, I did this experiment but I don't why blogger can't allow me to upload the videos. But basically, I failed! LOL! Maybe because the water was not purified enough or something else, but let me share my reflection with you guys! I find this science fact is so interesting and fun! Trying out myself felt so good. Alright, although the video next 2 slide shows my actually experiment and it failed, but I have learnt much more like how I should have handled this variable and that variable. I had learn new stuffs too! Next time, I believe I can do even better!:D

Hope you have enjoyed this week of science! Have a nice day!:D Enjoy!:D

My term 2 test results

Hey guys! Today, I will be sharing my term 2 test results! Well, I have a surprise for you so please continue reading!:DD

Alright, basically, in term 1, I have failed my test and although I've passed my re-test and got a c6 overall, I was kind of upset. And so, I decided to work hard and pay more attention in class during science lessons. When term 2 started, I tried to pay attention, tried to listen and not to slack during science class. However, I kept telling myself that aiya anyway just slack now, go home can study and yet I don't study when I got back home! So as time passes, I kept giving myself excuses until when the test was a few days away. So my science teacher gave a mock test just to get us prepared. When i looked at question 1, I didn't know how to do. So i skipped, jumped to questions that i can do slowly realise that I did not know how to do a single question! I was sad, disappointed and frustrated. So I begin to study 2 days before my test. First night I studies until like 3 in the morning and the next night till like midnight. During the test, I did my test.

After the test, I felt a little confident but yet still a little uncertain. Until the day I got back my results, I got B3!!!! YEAH!!! And guess what! I got 14/15 for MCQ!!! I felt so good and touched. Through this experience, I am not trying to tell you guys that you should slack until 2 days before your test and study till in the morning, I want to strongly encourage and advise everyone that DON'T WAIT TILL THE LAST MINUTE! Slacking a few times at first will only give you a temporary pleasure but when the test is here, it will go away. However, always paying attention is a permanent pleasure and when the test comes, you can put your knowledge to the test!

Guys, I hope that you understand what I am trying to say using this experience of mine. You might listen or not to my advise, I strongly encourage anyone who has problems to come approach me! Enjoy!:D

Lesson 4

Hey peeps! As promised, I will be teaching you guys about bases! Well, hope you've enjoyed the previous lesson. So now, let's get our asses into business!:D

What is a base?

-a substance that reacts with an acid to form a salt and water only.

-hydroxides and oxides of metals.

So, what is an alkali?

-a soluble base that produces hydroxide ions (OH-) when dissolved in water.

Important fact

ALL alkalis are BASES BUT NOT all bases are ALKALIS.

Reason?

-because alkali is a base that is soluble in water.

Like acids, there are strong alkalis and weak alkalis.

So, what does it mean to be an strong alkali??

-alkalis that ionise / dissociates completely in water to produce hydroxide ions (OH-). The properties and reactions are due to these hydroxide ions.

Then, what does it mean to be an weak alkali?

-alkalis that ionise / dissociates incompletely / partially in water to produce few hydroxide ions. The reactions are reversible.

From the above explanation, we can conclude that :

Strength of alkali depends of its degree of ionization/dissociation

What are the properties of bases and alkalis?

Bases :

1. react with acids to form salt and water only.

   2. react with ammonium salts to form salt, ammonia and water only.

   
   

Alkalis :

1. bitter taste and soapy feel

   2. turn red litmus paper blue.

   3. change the colours of the indicators

   4.react with a solution of one metal salt to give metal hydroxide and another metal salt.

   
   

Fun fact!

What happens when an acid reacts with a base??

Answer : Acids are neutralised by the base!

So, what is neutralisation??

-reaction between an aqueous acid solution and an aqueous alkali solution, the hydrogen ions from the acid combine with the hydroxide ions from the alkali to form water.

-at the same time, heat is given out during the process.

I bet you guys are also interested to know what are some of the uses of bases and alkalis!

Uses :

Ammonia solution:

(a) in window cleaning solutions

(b)in fertilizers

Calcium oxide:

(a) in neutralising acidic solution

(b)to make iron, concrete and cement

Magnesium hydroxide:

(a)in toothpaste to neutralise acid on teeth

(b)in antacids, to relieve digestion

Lesson 3

Hey people! I had a great today during science lessons! I hope you guys too!:D Well, today, I've learnt about new topics! They are acids and bases! But I will talking about acids this week!:D Basically, I have summarize the important points about this topic! I tried to make this topic as interesting as possible but do approach me if you have any doubts!:D Enjoy!:))

Before I start....

What is acid?

Is it something salty? Is it sweet? What is that??

Basically, acid is --> a substance which produces hydrogen ions as the only positive ions when it is dissolved in water.

Acid have 4 properties. They are :

1. They have a sour taste.
2. Dissolve in water to form colourless solutions which conduct electricity.
3. Acids turn blue litmus paper red
4. Reacts and metals, carbonates and alkalines.

Here are some examples of the strong acids :

1. Hydrochloric acid
2. Nitric acid
3. Sulfate acid

Here are some examples of the weak acids:

1. Ethanoic acid
2. Malic acid
3. Tartaric acid
4. Citric acid

So how do we know the strength of the acids?

-->The strength of an acid depends on its degree of dissociation / ionisation in water to form hydrogen ions.

Therefore,

STRONG ACIDS = 1)acids that ionise / dissociate completely in water to produce hydrogen ions

2)There are no molecules left.

3)The properties and reactions of acids are due to these hydrogen ions.

Weak Acids = 1)ionises / dissociates incompletely / partially in water to produce few hydrogen ions

Concentration

-amount of a solute dissolved in a unit volume of the solution

So what does it mean by a concentrated acid?

-->one in which the proportion of acid to water is very high.

On the other hand, diluted acid is...

-->one in which the proportion of acid to water is low.

Wait a moment, HAVE YOU EVER WONDER WHAT'S THE IMPORTANCE OF WATER FOR ACIDITY?

1. Pure acids exist as molecules instead of ions.
2. Pure acids do not behave as acids as the properties of acids are due to the presence of hydrogen ions.
3. When acids are mixed with water, ionization of acids occurs, and hydrogen ions are produced. Therefore, acids can only behave as acids when they are dissolved in water.

As mentioned above, one of the properties of acids is that they react with metals, carbonates and bases. Here are the 3 formulas :

For metal :

Acid + Metal --> Salt + hydrogen

Oberservations :

1) Effervescence observed. Colourless, odourless gas evolved which extinguished a lighted wooden splint with a ‘pop’ sound.

2)Grey solid reduced in size (when in excess). Grey solid dissolves to form a colourless solution

3)Heat liberated.

For carbonates :

Acid + Carbonates --> Salt + Carbon dioxide + water

Observations:

1) Effervescence occurs. Colourless, odourless gas evolved which reacts with calcium hydroxide to form a white precipitate.

2) white solid dissolves to form colourless solution

For bases :

Acid + Bases --> Salt & water

Observations:

1) Heat is given out

2)White solid dissolves to form colourless solution

OKAY, I bet you guys also want to know what are some of the uses for acids besides knowing their chemical formulas.

USES of Acids :

1. Sulfuric acids :

(a) in making detergents

(b) in making fertilizers

(c)in car batteries

2. Ethanoic acid :

(a) (in vinegar) to prepare food

(b) in making adhesives such as glues

3. Hydrochloric acid :

(a) in leather processing

(b) in cleaning metals

Alright! I'm done here! Will be talking to you guys about bases is next week! Enjoy!:DD

My term 1 test

Hey guys! Today, there will not be any lessons!! YAY!! haha oh back to the point, hmm, today I will be sharing with you guys about my science test.

How shall I begin with? Hmm, well, I have to admit that I did not revise a lot to prepare myself the test. Well, quite a few of the mistakes I had make in the test paper were concepts taught in the power point and I did not go and revise it. And you see, science can be easy as all you need to do is to memories the concepts of what you had learn because they are facts and they cannot be change. Back to reflection, through this test, I have learnt my lesson. I need to put in more effort in my science as it can really pull down my whole grades. It is NOT because it is counted in my grades and I study science for the sake for studying it. Science is going to be somehow useful to me in my daily life.

Guys, if you have done well in your science test then EXCELLENT JOB!! Keep it up!! For those who did poorly or not as good you wanted, learn from your mistakes and pick yourself up!! Do approach me if you have any doubts!!:D

Lesson 2

Hey guys! Daddy's home!:P oh yeah, alright back to business. Today, it is lesson 2 and I shall start now.

What is isotopes?

Isotopes are atoms of the same element with the same number of protons BUT different number of neutrons.

Examples: Carbon has 3 isotopes : carbon - 12, carbon - 13 and carbon - 14

Electronic configuration

-the way the electrons are arranged in an atom is called the atom's electronic structure or electronic configuration.

Examples: Nitrogen has 7 electrons.

Electronic configuration would be : 2.5

Argon has 18 electrons.

Electronic configuration would be : 2.8.8

Valence Shell

-the furthest occupied shell from the nucleus

Valence Electrons

-electrons in the valence shell

Note : ONLY valence electrons are in involved in chemical reactions.

Before we go to another topic, I got a little test for you.

-Describe how the elements in the periodic table are arranged.

Ans: The arrangements of the elements are arranged in an order of increasing proton( atomic) number.

Formation of ions

-During chemical reactions, some atoms might lose/gain electron(s). An atom becomes an ion(charged particle) when it lose/gain electron(s).

Alright, use the concept of what I had just written and think about this question :

Why does an atom become a charged particle when it gains or loses electron(s)?

-Ans : When an atom loses of gains electron(s), the positive and negative charges are not balanced. And therefore, the atom becomes a charged particle.

Formation of Cations

-When an atom loses 1 or more electrons, it becomes a positively charged particle called cation.

Example : Lithium atom(Li) Lithium ion(Li+)

3 protons 3 protons

3 electrons 2 electrons

Net charge : 0 Net charge : +1

Formation of Anions

-When an atom gains 1 or more electrons, it becomes a negatively charged particle called anion.

Example : Fluorine atom(F) Fluorine ion(F-)

9 protons 9 protons

9 electrons 10 electrons

Net charge : 0 Net charge : -1

You might be wondering why atoms become ions?? WHY??

Ans : To obtain a full valence shell

-To obtain the same electronic structure of a noble gas so as to be stable. ( Note : Nobel gas will be covered in the next lesson)

Alright, I hope you have learnt some new concepts such as what is cations and anions. Try to understand the concepts and do not hesitate to ask me if you have any doubts. ENJOY!:D

Lesson 1

Hey guys!! Well today, I shall start my lesson officially. Alright, back to business, today I will be teaching you guys what is atomic structure.

Remember??

An atom is the smallest unit of an element, having the properties of the element.

Now, think about this. Are atoms small solid balls with nothing inside??

Ans : No. Why no?? Well, we are going to answer that question through this question.

Atoms -- made up of subatomic particles ( refer to the top image)

Particle Symbol Relatively mass Charge

Proton P 1 1+

Neutron N 1 0

Electron E 1/1836 1-

Wait a second, why is the term "relatively mass" used rather than the term just mass?

Before you can answer the question, let me give you some hints :

Mass of of proton =~1.67x10-27 kg.

Mass of neutron =~1.67x10-27 kg.

Mass of electron =~9.11x10-31 kg.

Well, mass of proton, neutron and electron are too small and inconvenient to work with and thus by using relative mass, we do not have to remember to the exact value of the various masses.

Proton number

-the number of protons in an atom is called the proton number. It is also be known as the atomic number.

To count the number of neutrons in an atom,

Firstly, you have to understand what is Nucleon number.

Nucleon number

-nucleon number is the number of protons and neutrons in the nucleus of an atom.

-it is also called as the Mass number.

Nucleon number (Mass ) number = neutrons + protons

The center of an atom is called the nucleus and it contains the number of protons + number of neutrons.

Electrons

As you all know that electron is a negative charge, now as you can refer from the top picture, electrons are arranged in shells (orbits) at different distances from the nucleus.

Note : Shells are also called energy level.

Each shell can hold a certain maximum number of electrons of.

(a) 1st shell : 2 electrons

(b)2nd shell : 8 electrons

(c) 3rd shell : 8 electrons (the 1st twenty elements)

Now, let me give you a little test.

Why is an atom electrically neutral?

Number of electrons = number of protons. Equal positive and negative charges.

However, why is the nucleus positively charged?

The nucleus contains protons and neutrons. As protons are positively charged while neutrons are electrically neutral, and thus the nucleus is positively charged.

Alright, that's all for today's lesson. Well, go and digest what I had taught here and be prepared for the next lesson!:D