We covered mostly chemistry this term. Much about the periodic table was taught to us. This include atomic structure, chemical bonding, equation writing and acids, bases and salts. We had many hands-on experiences in the lab which help us to see clearly the experiments right in front of our very eyes.
Firstly, we covered acids alkali and bases.
Acids: An acid is a substance which produces hydrogen ions as the only positive ions when it is dissolved in water.
Alkali: An alkali is a metal hydroxide which is soluble in water and produces hydroxide ions (OH-) in water.
All alkalis are bases but not all bases are alkalis.
Bases: Bases are the oxides or hydroxides of metal that reacts with an acid to form a salt and water only.
To test acidity, we use different indicators to test different pH. They are: methyl orange, universal indicator, red litmus paper, blue litmus paper and phenolphthalein.
The use of red litmus paper and blue litmus paper is to test acidity whereby the paper would change colour. For example, if the solution is acidic, the blue litmus paper would turn red while the red litmus paper would remain red, showing us that it is acidic.
Next, the use of Methyl orange is to test acidity. Methyl orange will only change its colour at pH 4. It will turn red in acid and remain the same as orange in alkali
Next, the use of phenolphthalein is to test whether a solution is an alkali and it will change colour at pH 9. It is colourless in acid and pink in alkali, thus only useful when testing for alkali.
Lastly, the use of the universal indicator is the most useful. It can be used to test all sort of solutions, being able to test both acidity and alkali with a big range.
I feel that this topic is interesting yet challenging. I faced many problems like memorising the periodic table and memorising the formulas(reactions and indicators to measure acidity). This proved to be a big challenge for me. However, with constant practice from the teacher and constant revision, I manage to grasp hold of the concept, even though I was not very good in this subject.
I feel that this topic is interesting as we get to do many lab lessons on this topic and it is very cool to find acidity and to know that many things around us revolve around this concept.
I also learnt more about periodic table and atomic structure.
Every element is given a name and a chemical symbol. A periodic table is a table of elements for us to refer to check what is the atomic structure and other infomation about the element.
In the periodic table:
Each vertical column is called a group.
Each group has its own unique chemical properties whereby the elements in the group have similar chemical properties..
Each horizontal row is called a period.
Elements in a period from left to right shows a gradual change from metallic properties to non- metallic properties.
Each element is represented by chemical symbol.
For example, Oxygen is O.
Chemical bonding is basically whereby two elements and atoms bond together so as to make the other element neutralized. Thus the two elements bond together to "help" each other.
Term 1 test:
I did not do well. I barely passed with a C6 grade. However, I felt that I did not study enough for this term and will strive harder for next term and acquire better results.
