Term 1: Under The Hood

I would say that term 1 was the first time I ever felt that I have learned something in science lessons, as we finally have to opportunity to dwell into the deeper, more complex parts of science. We learned about atoms and molecules, and the subatomic particles that they are made of. One of the most unforgettable experiences was the time where we were told to research on the history of the “model of the atom” through time. This was one of the most exciting and fun research works I have done in science as I learned a lot from it. Through that single assignment I learned about people like Ernest Rutherford, James Chadwick and Neils Bohr, and made me go on to read about stuff like the Manhattan project, in which Rutherford was involved.

All we learned was basically that in an atom, there are three types of subatomic particles, the neutron, with a neutral charge, an electron, with a negative charge and a proton, with a positive charge. Every atom would have a neutral charge, which means that it would have equal numbers of electrons and protons. We learned terms like the nucleon number of an atom is the number of subatomic particles in the nucleus of the atom, which means the total number of protons and neutrons in that atom and terms like atomic number which is the number of protons in an atom, or in other words the number of electrons. We learned that electrons are arranged in shells, with every shell a maximum number of electrons, and the out most shell is called the valence shell. However electrons can be gained, lost or shared, and atoms with lost or gained electrons would be called ions. All atoms would want to achieve an octet structure, meaning a full valence shell, which makes them gain and lose electrons to other atoms. The gaining, losing and sharing of electrons result in the bonding of the atoms, forming compounds. There are two types of chemical bonding, covalent bonding and ionic bonding. Covalent bonding is the sharing of electrons in the valence shell between atoms, and ionic bonding is achieved through the attractions between two atoms with different charges, neutralizing each other. We also learned about isotopes, which are elements with differing numbers of neutrons. One common misconception we had was to think that the nucleon number determines the chemical properties of an atom, but in fact only the atomic number affects the chemical properties, meaning that same elements can have different numbers of neutrons. With this knowledge we went on to explore about acid and bases in the laboratory.

I think that these laboratory lessons on Acids and Bases were one of the most interesting ones I have ever done. We got the chance to see how the chemical reactions between acids and bases, acids and alkalis, acids and metals, acids and carbonates and acids and ammonium salts look like, which gave us a deeper impression of it, aiding our memory. I had always felt that laboratory lessons were a waste of time, taking up one and a half hours and achieving nothing but these small experiments were actually more fun than I expected them to be. One of those memorable lessons was when we were doing the experiment on the reaction between acids and metals. We were given four types of metals, magnesium, copper, zinc and iron. Other than the information we were supposed to gather, we went an extra mile by “testing” what color is produced when those four metals are burned. And we did get results, although it came with some scolding, that copper burns in a green flame, zinc burns in a bluish-white flame, and iron did not burn. However I still think that with the cooperation between student and teacher, lab lessons can be more efficient less time consuming, as a lot of time is wasted due to the lack of cooperation, for instance, students fooling around.

Now for my opinions on my term test, well, it was satisfactory, but I could have gotten a higher grade. I would say that this test was an easy one, and so I should have done better. Careless mistakes were made for example forgetting to label the charge when drawing the electronic configuration of magnesium ion. Another foolish mistake was to get the format of the formula of two atoms wrong, when it was written on the white board. These mistakes cost me two marks, and another screw up was to not memorize the chemical reactions by heart, which cost another three marks. I would rate my performance in this test an 8 over 10, but this test clearly showed one of my fatal flaws, and I hope to address it in my following test.

SUMMARY

ATOMS & IONS & CHEMICAL BONDING

An atom has neutrons (NO CHARGE) protons (POSOTIVE CHARCE) and electrons (NEGATIVE CHARGE). Neutrons and protons are located in the nucleus of the atom, and electrons orbit around the nucleus in shells. Atoms can have different number of neutrons, and atoms with different number of neutrons but same number of protons is called isotopes. Isotopes have similar chemical properties. Atoms naturally have the same number of electrons and protons, thus having no charge. The maximum number of electrons in the first shell and second shell is 2 and 8 respectively. The outmost shell in an atom is called the valence shell, and the number of electrons the shell is short of forming a full shell is called the valency of the atom. If the valency is below half of the number of maximum electrons possible in that shell, that atom would lose electrons and if it is more than half, they would gain electrons from other atoms. Atoms with gained or lost electrons are called ions. Atoms can bond together to form compounds. There are two types of chemical bonding, covalent bonding and ionic bonding. Ionic bonds are formed when two or more ions have opposite charges that cancel each other out, causing attractions between the ions, making the bond. Covalent bonds are formed by the sharing of electrons of two or more atoms, and this sharing form the bond between the atoms.

ACIDS AND BASES

Common acids: Hydrochloric Acid (HCl)
Nitric acid (HNO3)
Sulfuric acid (H2SO4)
Ehtanoic acid
Citric acid
Tartaric acid

Alkalis: Metal hydroxides that are soluble in water and ionize to form hydroxide
ions (OH-).

Bases: Metal hydroxides or metal oxides

All alkalis are bases, but not all bases are alkalis.


Reactions:
Metal + Acid => Salt + Hydrogen
Sulfuric acid + copper => Copper (II) Sulfate + Hydrogen
H2SO4+Cu => CuSO4 + H2

Acid + Carbonate => Salt + Carbon-Dioxide + Water
Sodium Carbonate + Sulfuric acid => Sodium sulfate + water + carbon-dioxide
Na2CO3 + H2SO4 => Na2SO4+ H2O + CO2

Acid + Base => Salt and Water
Magnesium oxide + Sulfuric Acid +> Magnesium sulfate + Water
MgO + H2SO4 => MgSO4 + H20

Base + Ammonia Salt => water + Ammonia + salt
Sodium Hydroxide + Ammonia Chloride => Ammonia + Water + Sodium Chloride
NaOH + NH4Cl => NH3 + H20 + NaCl