Types of forces
Some examples of forces would include friction, weight, magnetism and gravity but mass and speed are not forces. These types of forces mentioned can be further classified into contact forces and distance forces. Friction and weight are contact forces while magnetism and gravity are distance forces.

Newton’s Laws
Newton enumerated his Three Laws of Motion and they are as follows.

#1: Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it. 

This is perhaps more commonly known as the law of inertia and this means to say that objects at rest stay at rest and objects at motion stay in motion unless a force is applied to it. Without a force, it will just keep doing what it was doing in the first place. This is called inertia. However, the force that opposes it is friction and thus, Newton’s First Law is accepted.

#2: The relationship between an object’s mass m, its acceleration a, and the applied force F is F = ma. Acceleration and force are vectors (as indicated by their symbols being displayed in slant bold font); in this law the direction of the force vector is the same as the direction of the acceleration vector.

This, according to some, is his most powerful law of motion. It explains three things. Firstly, if you place a force on an object, it will accelerate and it will change its velocity in the direction of the force. Secondly, this acceleration is directly proportional to the force. For example, if you are pushing on an object, causing it to accelerate, and then you push three times harder, the acceleration will be three times greater. Thirdly, this acceleration is inversely proportional to the mass of the object. For example, if you are pushing equally on two objects, and one of the objects has five times more mass than the other, it will accelerate at one fifth the acceleration of the other.

#3: For every action there is an equal and opposite reaction.

The statement means that in every interaction, there is a pair of forces acting on the two interacting objects. The size of the forces on the first object equals the size of the force on the second object. The direction of the force on the first object is opposite to the direction of the force on the second object. Forces always come in pairs – equal and opposite action-reaction force pairs.

Apparatus included 1 casstte box containing bufffers (1-14), 1 more cassette box containing the universal indicator, natural indicator (cabbage extract), methyl orange and phenolphthalein. There is also 2*”14″ wells strips and 2*”6″ wells strips. Materials included red and blue litmus paper, ethanoic acid, dilute hydrochloric acid, dilute sulfuric acid, aqueous ammonia, dilute sodium hydroxide and de-ionised water.

Part 1 of the procedure is to place 1 drop of universal indicator and 7 drops of different buffers into a “14″ wells strip then set the colour scale with glue gun. Record the colours of the buffer solutions with universal indicator in the table and repeat procedure 1 and 2 by using 2 drops of natural indicator and 7 drops of different buffers into another “14″ wells strip. Record the colours of the buffer solution with the natural indicator in the table.

Part 2 of the procedure is to half fill a “6″ wells strip with the following reagents in the same order: ethanoic acid, dilute hydrochloric acid, dilute sulfuric acid, aqueous ammonia, dilute sodium hydroxide and de-ionised water. Dip a red and blue litmus paper into the 6 reagents and record the observations. Add one drop of methyl orange into the 6 reagents and record the observations. Repeat step 1 using the second “6″ wells strip. Repeat step 3 using one drop of phenolphthalein. Place one drop of ethanoic acid on your finger and taste. Place one drop of dilute sodium hydroxide on a finger and rub it against the thumb.

Reflections:

The results are then collated. From this experiment, I really learnt a lot as firstly, it was my first experiment this year and it finally involved acids and alkalis, something that was not tried before. In the end, I got an A for the practical and have worked really well with my lab partner. I look forward to future co-operations with him again and strive to achieve better results. Also, we should also know that not only acids are corrosive but alkalis are too. This has been a misconception since very long ago. We should really take caution and understand the properties of acids and alkalis.

The rationale of our project is to investigate if alkaline water really helps antioxidants function better to counter the free radicals in our body and so our hypothesis is that the higher the pH, the faster the reaction between antioxidants and free radicals. We used many chemicals including ABTS, HCL, NAOH and NACL and antioxidants including red tea, ginger tea and Vitamin C solution. Our methodology firstly is to put 3ml of ABTS into a curvette and test for light absorbance first in the UV-Vis Spectrometer and record the results. Next, we add 25µl of antioxidant into the same curvette and test for light absorbance.

Using this formula of  Light absorbance = (light absorbance of ABTS with chemicals – original light absorbance of ABTS)     divided by original light absorbance of ABTS ×  100%, we get the final results that would be used to make the graphs for the presentation.

What will happen is that-

Term 1 tested on the periodic table, atomic structure, ionic and covalent bonding. I knew that I had done badly for this paper as I had not revised enough. I was unable to keep up in class sometimes as I could not understand all the things taught at once. I had revised the notes but  Icould only understand a bit of it. After the paper, I told myself that I had to strive harder and to achieve better results.

For term 2, equation writing, acids and bases and the reflection of light was tested. This test was easier as compared to the fist test and I improved by three grades. Although this is not what I hoped to get, I knew I worked hard. I was good at writing equations but drawing diagrams in physics was another big headache as I really couldn’t understand. I once again strived to do better in the next test.

Lastly, in term 3, refraction of light, lens, colours of light and ecosystem were tested and I achieved a B4. This topics were course heavy in the sense that there were many things to memorise and there were more ray diagrams which had to be practiced. I was quite fortunate as without the ecosystem portion, I think that I would have failed that paper. So now, as the EOY papers await me,  I really hope that I can do the best for the exams and achieve at least an A.

From this results, if I break down into physics, chemistry and biology, I know that my lousiest would be physics, chemistry and my best being biology. I am able to get the grasp of biology and catch up in class whether for ecosystem or the human reproduction. I am also more interested in this subject as I am more willing to read up. However, for chemistry and physics, halfway in the lesson I get super lost. For physics, I am unable to get the grasp of drawing and understanding the topics taught. I will do more practices at home in future so as to boost up the knowledge and enable me to do better next time.

Modern Periodic Table

The periodic table was firstly created by a chemist known as Dmitri Mendeleev in 1869 where he had arranged all the known elements in order of their relative atomic masses and arranged it all in horizontal rows so that the elements with similar properties were in the same vertical column. In the periodic table, the vertical columns of similar elements are called groups whereas the horizontal rows of elements are called periods. The one that Mendeleev created at first was eventually changed to the one above which is called the modern periodic table with the major difference being the position of transition elements. The elements in the table are arranged such that it is according to the proton number and the symbol representing the element eg. H for hydrogen, He for helium and so on…

Now, in the periodic table, each group has its own names and properties and I will be explaining about several groups in detail below:

For Group 1, we have the alkali metals. The alkali metals are called this because when reacting with water, they form alkaline solutions and they are super reactive that they must be stored under oil to prevent them from reacting with oxygen and water vapour in the air. They have low meting and boiling points as compared to other metals but they fall from Li to Fr. They also have lower densities as compared to other metals. Their reactivity also increases as the group goes down.

Next for Group 7, those are the halogens. They are a group of reactive non-metals that are super reactive and can combine with metals and salts. Their melting and boiling points are quite low but are also such that it goes up as we go down the group from Flourine to Iodine. These halogens exist as simple molecules meaning that they can separate easily.

Lastly for group 8, we have the noble gases. They are all colourless and very unreactive as their melting points, boiling points and densities all show steady change as their atomic mass increases. Uses of the gases include, helium, which also is for weather balloons. Neon, for the neon lights, argon and krypton in electric light bulbs and so that is what the noble gases are all about.

From all this above, I feel that what Mendeleev has done was really impressive as he was the only one at that time to be able to put together all of the elements in the world and look and study their properties to be able to create groups and periods with relevance. I know that as time goes, there would be more and more elements found on this earth and people would be able to add into this periodic table.

Firstly for the natural method which includes the rhythm and withdrawal methods. The rhythm methods makes the woman track her menstrual cycle and avoid having intercourse during the fertile period. This is temporary but unreliable as the menstrual cycle is easily disrupted by the hormonal fluctuation in the woman’s body. As for the withdrawal method, it is also only temporary and unreliable as the sperms would be present in the pre-seminal fluids and the man may not be able to withdraw in time.

Next for the chemical method, it makes use of the spermicide which is also a chemical which is sprayed into the vagina to kill the sperms upon entry and render them unable to swim up to the oviducts. This is also temporary but is 80% effective as some sperms may be resistant and still be able to survive the journey.

For the chemical methods which includes the use of condoms and diaphragm, both are again temporary and is 99.99% effective. For a condom, it is a rubber sheath worn over the penis to collect the sperms and prevent them from entering the vagina. The reason that it is not 100% is because microscopic tears may be present and the sperms will eventually break through. For the diaphragm, it is a rubber cap fitted over the cervix and acts as a barrier between the sperms and the ovum. The problem is that if the cap is not fitted properly, sperms can still enter the uterus and swim up to the oviduct.

Next, for hormonal methods, we have the pill and the injection/implant. This pill is taken by the women to prevent ovulation. However, there are also many cases of woman still getting pregnant even though they consumed it. This is also a daily process as the woman have to take it everyday to stabilise the hormones. As for the injection/ implants, it is temporary as synthetic female hormones are regularly injected from a tube to the blood stream to prevent ovulation but as again, there were cases of woman still being pregnant after this.

Lastly for the surgical aspect, we have the ligation for the women and vasectomy for the men. How they work? Ligation is permanent as the oviducts are cut and tied up to prevent the sperms from meeting. This method is 100% effective. As for vasectomy, the sperm ducts are cut to prevent sperms from being released into the urethra and out of the penis. It is also permanent and 100% effective.

From all this, I feel that although the last two methods are 100% effective, they are permanent meaning that what’s done is done and it is not reversible. One should think through before really making the decision. Personally, I would not recommend this to anyone as I believe that although at that point of time you do not want a baby, it can be for later. For me the mechanical use would be the best as condoms are cheap and it works most of the time. As for a diaphragm, the chances for a doctor to not fit the cap properly is quite minimal and therefore I would feel that it is quite safe.

Going back to Africa, as there are not many experienced doctors to place the cap into the woman’s vagina, I believe if possible they should be using a condom as it would really help a lot. After all this, I really learnt that this birth control methods are really very important and if you are not ready, this can help you.

Regards,

Timothy

Cheers,

Timothy

Firstly, this is the newest blog that I have created and this blog is for school purposes. This is a blog carried forward from my secondary one year and that with a lot of editing and deleting, this is back to a blank blog, with this greeting post being the first post. Firstly, I would like the public to respect this blog  and not comment on the posts with vulgarities and obscenity. All these will not be tolerated and they will be deleted.

Cheers,

Timothy