Search results
Results from the WOW.Com Content Network
GCSE Bitesize was launched in January 1998, covering seven subjects. For each subject, a one- or two-hour long TV programme would be broadcast overnight in the BBC Learning Zone block, and supporting material was available in books and on the BBC website. At the time, only around 9% of UK households had access to the internet at home.
Key Stage 3 (commonly abbreviated as KS3) is the legal term for the three years of schooling in maintained schools in England and Wales normally known as Year 7, Year 8 and Year 9, when pupils are aged between 11 and 14. In Northern Ireland the term also refers to the first three years of secondary education.
the digit "ten" in hexadecimal [2] and other positional numeral systems with a radix of 11 or greater [3] the unit ampere for electric current in physics [4] the area of a figure [5] the mass number or nucleon number of an element in chemistry [6] the Helmholtz free energy of a closed thermodynamic system of constant pressure and temperature [7]
The conversion of a portion of the chemical energy to heat at each step in a metabolic pathway is the physical reason behind the pyramid of biomass observed in ecology. As an example, to take just the first step in the food chain : of the estimated 124.7 Pg/a of carbon that is fixed by photosynthesis , 64.3 Pg/a (52%) are used for the ...
The characteristic reaction of fullerenes is electrophilic addition at 6,6-double bonds, which reduces angle strain by changing sp 2-hybridized carbons into sp 3-hybridized ones. The change in hybridized orbitals causes the bond angles to decrease from about 120° in the sp 2 orbitals to about 109.5° in the sp 3 orbitals. This decrease in bond ...
The control of the symmetry of molecules produced in modern chemical synthesis contributes to the ability of scientists to offer therapeutic interventions with minimal side effects. A rigorous understanding of symmetry explains fundamental observations in quantum chemistry , and in the applied areas of spectroscopy and crystallography .
A drawing of a butterfly with bilateral symmetry, with left and right sides as mirror images of each other.. In geometry, an object has symmetry if there is an operation or transformation (such as translation, scaling, rotation or reflection) that maps the figure/object onto itself (i.e., the object has an invariance under the transform). [1]
The 10 to 1 ratio was an estimate made in 1972; current estimates put the ratio at either 3 to 1 or 1.3 to 1. [301] The total length of capillaries in the human body is not 100,000 km. That figure comes from a 1929 book by August Krogh, who used an unrealistically large model person and an inaccurately high density of capillaries.