Reflection #1 (Alda8A)

Today, 16 January 2014.

Today in chemistry lesson I learn about how to write chemical formula and naming compound, in this case we are reacting metal with non-metal. These are some examples I learned during the chemistry lesson:

For example we want to react Sodium with Sulphur, the first thing we need to know is the oxidation number of each of the element by looking through the periodic table (the group number), from left to right, the oxidation number for each row will be +1, +2, (and skip the transition metals) +3, +4, -3, -2, -1, 0. After determining the oxidation number of each element, sodium (Na) is +1 because its the most left and sulphur (S) is -2 because its the 6th rows. We know that sulphur has a bigger number of oxidation, we need to cross multiply the number of oxidation for each of element. So Na+1 S-2 will become Na2S after we cross multiply which means now there are 2 sodium and 2 sulphur which means that its balanced.

I also learn that if the element is monoatomic, like Nitrogen (N), Oxygen (O) etc, we need to change the last words using "ide" so if its nitrogen, it'll become nitride, oxygen become oxide. However if its polyatomic like Na3, the nitrogen will be replaced with ate so it becomes nitrate. If Na2 it'll become nitrite.