Chapter 2: Atoms and Molecules
An atom is the smallest particle of an element. It is made up of: protons, neutrons and electrons.
Protons
-Symbol: p
-Has a relative mass of 1
-Has a positive charge
Neutrons
-Symbol:n
-Has a relative mass of 1
-Has a neutral charge (0).
Electrons
-Symbol: e
-Has a relative mass of 1/2000
-Has a negative charge
The nucleus of the atom consists of protons and neutrons. The total number of neutrons and protons is called the nucleon number. Electrons move around the nucleus in fixed orbits.
The number of protons and electrons are actually the same (for example, if the atom has 8 protons, you will know it has 8 electrons). To determine the number of neutrons, subtract the proton number from the mass number to know the number of neutrons the atom has (for example, if the proton number is 17 and there are 8 protons, the number of neutrons is 9).
Examples of positive and negative ions |
I've also learnt about molecules are formed from atoms too. Some share electrons with other atoms by combining to form molecules. There are two types of molecules: Molecules of Elements and Molecules of Compounds. Molecules of elements usually consist of a fixed number of the same type of atom. several examples of such molecules are hydrogen gas, oxygen gas and bromine gas. Molecules of compounds are made up of a fixed number of different types of atoms Such examples of these molecules are water, carbon dioxide and ammonia. The Particulate Model of Matter consists of particles but they can be refined to molecules, For example, liquid particles are actually molecules made up of 2 hydrogen atoms and an oxygen atom.
I've learnt how to write chemical formulas, which tells us the type and number of each type of atom present in one molecule of the substance.
Examples:
Water - H20: It's made up of 2 Hydrogen atoms and 1 Oxygen atom
Glucose molecule - C6H12O6: It's made up of 6 Carbon atoms, 12 Hydrogen atoms and 6 Oxygen atoms
I find the knowledge of atoms very useful, as I now know what exactly are matter made up of, and the different types of products formed when atoms are chemically combined together. Before learning this topic, I only knew what is oxygen and carbon dioxide, but not what it is made of. However, now I know, and I feel more knowledgeable.
Chapter 1: The Particulate Model of Matter
Everything around us is matter, but what exactly is matter made up of?? Now I know. It's made up tiny particles, which are arranged in a pattern and are constantly moving about. The particles in each state of matter are arranged differently and move at different speeds.
I see...
-that the 3 states of matter are related as they change from one form to another each time heat is applied due to the different arrangements of the particles.
-when heat is applied, the particles are arranged differently, spreading further apart in each state.
-when heat is lost, the particles' movement is less hectic.
I think...
-with the particulate model of matter, the processes of melting, condensation, boiling and freezing can be better understood.
-the different states of matter is now easier to understand, as we know why some matter can be compressed whereas why others can't.
-one is able to explain daily life situations, such as the melting of ice in a drink, with the Particulate Model of Matter
I wonder...
-what will happen if the particles cease moving.
-why do particles have to be in constant motion.
Lesson 6: FRUITY DNA!! Wednesday 29 September 2010
Lesson 4: Cells Exploration Monday 20 September 2010
That day, we were to work in groups of 3 or 4 to create a magnified version of a cell. My group, which consists of Zulhilmi, Wei Wen and me, decided to create an animal cell. We were supposed to choose some materials from the front of the laboratory to use in our cell. Wei Wen and I chose almost everything to put in the agar-agar, which is the cytoplasm of the cell. At first, we were at a loss as we had a huge supply of materials. However, we sorted the different parts of the cell out and decided on the material to be used to represent the cell part. We managed to successfully use all the materials we have taken. During the process of creating our animal cell, Wei Wen took plentiful photos. We were to use these photos to come up with a photo story. Simply put, it means that we have to arrange these pictures in an order to tell a cell story.Zul also took several snapshots of our final product together with Wei wen from different angles. I feel that this hands-on experiment is a really interesting way to learn about the cell parts and where they are located. Instead of reading from textbooks, we are able to have fun and at the same time, learn about cells. I hope that we are able to conduct more of these kind of experiments!
Lesson 3: Interview Thursday 16 September 2010
Everyone in the class was to be interviewed by Mdm Riza to see if we were suitable for the job we were applying. I felt really nervous about this interview for I wanted to impress the interviewer. However, I feel that I could have done a better job during the interview. This is a point which I need to work on so that I could be a better presenter in the future. We were also given a worksheet to complete when waiting for our turn to be interviewed. The worksheet was to test our knowledge of the different parts of an animal cell and its functions and how important it was to keep the cell healthy.