Chemical Science: Chemistry of

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Tuesday, 29 January 2013

Why Are Humans Made Of Carbon? Chemist Points To Electrons, Molecular Bonds

Everything on earth is made up of combinations of different elements – all of which can be found on the periodic table. Considering that the periodic table contains 118 elements it seems a pity that organic life tends to feature only five or six of those elements in any vast quantities. The main one being carbon.

As well as being the main element in organic matter, carbon atoms are the only element in both graphite and diamond.

It would be impossible for life on earth to exist without carbon. Carbon is the main component of sugars, proteins, fats, DNA, muscle tissue, pretty much everything in your body. The reason carbon is so special is down to the electron configuration of the individual atoms. Electrons exist in concentric ‘shells’ around the central nucleus and carbon has four electrons in its outermost shell. As the most stable thing for an atom to have is eight electrons, this means that each carbon can form four bonds with surrounding atoms.

For more click here.

Credit: http://www.huffingtonpost.com

Monday, 28 January 2013

Chemistry of Cooking

WHAT ARE ACIDS AND BASES? An acid is defined as a solution with more positive hydrogen ions than negative hydroxyl ions, which are made of one atom of oxygen and one of hydrogen. Acidity and basicity are measured on a scale called the pH scale. The value of freshly distilled water is seven, which indicates a neutral solution. A value of less than seven indicates an acid, and a value of more than seven indicates a base. Common acids include lemon juice and coffee, while common bases include ammonia and bleach.

WHY DOES FOOD SPOIL? Processing and improper storage practices can expose food items to heat or oxygen, which causes deterioration. In ancient times, salt was used to cure meats and fish to preserve them longer, while sugar was added to fruits to prevent spoilage. Certain herbs, spices and vinegar can also be used as preservatives, along with anti-oxidants, most notably Vitamins C and E. In processed foods, certain FDA-approved chemical additives also help extend shelf life.

This report has been produced thanks to a generous grant from the Camille and Henry Dreyfus Foundation, Inc.

Reported January 2009

Credit: http://www.ivanhoe.com/science/story/2009/01/528si.html

Tuesday, 27 November 2012

The Physiology Of Crying

There are three types of tears. The first type is basal tears. Because the eyeball's surface is riddled with irregularities, basal tears create a thin coat over the eye which smoothes out the surface. This helps to protect and lubricate the eye. Without this lubrication, a person would see a very distorted picture, and it would be painful when the eyeball moves. The eye needs this coating all the time so the body must constantly replace these tears due to the loss caused by evaporation. A typical person will produce five to ten ounces a day. In addition, basal tears contain antibacterial chemicals.

Subhashitham

उद्यमेनैव सिध्यन्ति कार्याणि न मनोरथै: ।
न हि सुप्तस्य सिंहस्य प्रविशन्ति मुखे मृगा: ॥

अयं निज: परो वेति गणना लघुचेतसाम् ।
उदारचरितानां तु वसुधैव कुटुम्बकम् ॥

न कश्चिदपि जानाति
किं कस्य श्वो भविष्यति ।
अतः श्वः करणीयानि
कुर्यादद्धैव वुद्धिमान् ॥

आचार्यात् पादमादते पादं शिष्यः स्वमेधया ।
पादं सब्रह्मचारिभ्यः पादं कालक्रमेण च ॥

उपकारिषु यः साधुः सधुत्वे तस्य को गुणः ।
अपकारिषु यः साधुः स साधुरिति कीर्तितः ॥

च्छायामन्यस्य कुर्वन्ति तिष्ठन्ति स्वयमातपे ।
फलान्यापि परार्थाय वृक्षाः सत्पुरुषाः इव ॥

जलबिन्दुनिपातेन क्रमशः पूर्यते घटः ।
स हेतुः सर्वविद्यानां धर्मस्य च धनस्य च ॥

अग्निशेषमृणशेषं शत्रुशेषं तथैव च |
पुन: पुन: प्रवर्धेत तस्माच्शेषं न कारयेत् ||

पृथिव्यां त्रीणि रत्नानि जलमन्नं सुभाषितम् |
मूढै: पाषाणखण्डेषु रत्नसंज्ञा प्रदीयते ||

नाभिषेको न संस्कार: सिंहस्य क्रियते मृगैः |
विक्रमार्जितराज्यस्य स्वयमेव मृगेंद्रता ||

स्वभावो नोपदेशेन शक्यते कर्तुमन्यथा ।
सुतप्तमपि पानीयं पुनर्गच्छति शीतताम् ॥

यस्मिन् जीवति जीवन्ति बहवः स तु जीवति ।
काकोपि किं न कुरुते चञ्च्वा स्वोदरपूर्णम् ॥

दनेन तुल्यो विधिरास्ति नान्यो
लोभोच नान्योस्ति रिपुः पृथिव्या ।
विभूषणं शीलसमं च नान्यत्
सन्तोषतुल्यं धनमस्ति नान्यत् ॥

संरोहति अग्निना दग्धं वनं परशुना हतं ।
वाचा दुरुक्तं बीभत्सं न संरोहति वाक् क्षतम् ॥

अहो दुर्जनसंसर्गात् मानहानिः पदे पदे ।
पावको लोहसंगेन मुद्रगरैरभिताद्यते ॥

द्वौ अम्भसि निवेष्टव्यौ गले बद्ध्वा दृढां शिलाम् । धनवन्तम् अदातारम् दरिद्रं च अतपस्विनम् ॥

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