Posts

Showing posts from December, 2012

Periodic Trends in Atomic Properties

Image
History of the universe In this section, we will try to see the trends in atomic properties of the periodic table, especially on s and p -block elements. The properties that wee will have a look are radius, ionisation energy, electron affinity, and electronegativity. Besides that, we will see how the electronegativity can predict the element characterisitic (metal, metalloid, and non-metal). Before we see its trends, we will have a quick journey at beginning of the universe. At the beginning of the universe, there were no elements or atomic nuclei; the atomic nuclei were formed around 1 minute after the big bang. Around 1 minute after the big bang, the universe had cooled sufficiently to form stable protons and neutrons. Then, protons and neutrons can fuse to give deuterium (H-2), isotope of hydrogen, nuclei. Then, deuterium nuclei fused to give stable He-4. After 3 minutes after the big bang, the universe is too cool for nuclear fusion to continue, so only light nuclei were for

Group 14 Elements

Image
In this part we will have a brief view about group 14 elements. This part will see the occurrence of group 14 elements, the chemical properties (1st ionisation energy and electron affinity, covalent radius, and Pauling electronegativity scale), the physical properties (melting and boiling point), the allotropes, and the compounds of group 14 elements (the oxidation states, oxides, and chlorides).  From left to right: carbon, silicon, germanium, tin, and lead

Acid and Base in Organic Chemistry

Image
Acidity describes the tendency of a molecule to release a proton and can be quantified by acid dissociation constant ( pK a ). All molecules containing hydrogen have the potential to act as an acid and in chemistry the pK a value also has a reference point or reaction. In this case the reaction of acid with water. Understanding of acidity trends in organic chemistry is very useful later on, especially to predict the mechanism reaction. From the equation above, we can simplify the if the acidity strength increases as value of pK a decreases.

Washing It All Down: The Chemistry of Drinks

Image
As human being which comprises of 60% of water, liquid consumption is important to fulfill the nutrition as well for pleasure. In this section we will try to see the chemistry inside of our daily drinks. Since there are a lot of type of drinks or beverage in our daily life, we only discuss 3 types; Coca Cola, tea and coffee, and wine. The drinks

The Chemist's Recipe II: Spaghetti Bolognese

Image
Spaghetti Bolognese In this part, we will encounter another food recipe, spaghetti bolognese, from the point of view of a chemist. Spaghetti bolognese is a simpler dish than rice curry as we saw in previous article, but in point of view of a chemist is still a complicated dish as it comprises a lot of ingredient. In this section, we will try to focus on the main ingredients; garlic, lycopene from tomatoes, olive oil, and cooking meat. We will not discuss about the pasta because it is simply carbohydrate in similar way as rice (have a look in curry recipe ).

The Chemist's Recipe I: Curry Rice

Image
In this section, we will have a look the chemistry inside curry rice. We will have a brief description about the key chemicals inside this recipe as well the bioactivities of the molecule which has the function as nutrient. The Art of Cookery (1747) by Hannah Glasse Before we discuss the chemical compounds on curry and rice, it is better to have a quick overview about its history. The term of curry was used in English long before arrival of traders to the subcontinent and the first curry recipe in Britain appeared in The Art of Cookery Made Plain and Easy by Hannah Glasse in 1747. However, the early recipes did not include hot spices because chili plants were not introduced to India until the 1500's.

The Chemistry of Vitamins

Image
In this section, we will see about healthy eating, which will focus on the vitamins. Besides that, the chemistry of vitamin which helps to maintain the immune system will be discussed briefly. Moreover, since there are a lot of types of vitamin, we will see only vitamin A, C, and E in this section; vitamins is also about nutrient and neutraceutic. Vitamin B12