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How many electrons are there in the average bowl of cereal?
Wednesday, November 9th, 2011
Well typically breakfast consists of around 200 grams of cereal and roughly 200 millilitres of milk. For these purposes I will make some assumptions:
First assume that the cereal is made up completely of carbon. 12 grams of carbon contains approximately 6.023 x 1023 atoms of carbon (The Avogadro Number from earlier on). So 200 grams of carbon contains (200/12) ~ 17 x 6.023 x 1023 atoms. Each atom of carbon contains 6 electrons. So the final total is 6 x 17 x 6.023 x 1023 which comes to 6.14 x 1025 atoms.
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What is science?
Saturday, October 29th, 2011
The word Science is derived from the Latin word Scire – ‘to know’. It is probably related to the word ‘scindere’ (from which I think we get ‘scissors’) which means to split or separate – i.e. it means to sort things out.
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Is there any genetic link between insects and plants, that could explain mimicry eg. Mantis orchid
Tuesday, January 25th, 2011
The first part of the question can be answered in the affirmative; yes, there is a genetic link between insects and plants. In fact, there are genetic links between all living things. This is one of the amazing facts modern biology has revealed to us.
Then the second part: can this link be an explanation for mimicry eg. Mantis orchid? This is almost surely not the case. To find out why, we need to have a look at the relations between all living things according to the theory of evolution.
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Why split the atom?
Monday, November 15th, 2010
First of all the phrase ‘splitting the atom’ is a misnomer – atoms are ‘split’ all the time as they lose electrons in chemical reactions. The phrase really refers to ‘splitting the nucleus of an atom’. You can read more about this on my answer to the question What does “splitting the atom” mean?
Normally the nucleus of atoms is ‘protected’ deep within the atom. But it is possible to split the nucleus by hitting it with (for example): a neutron; a very fast moving proton ; or a collection of two protons and two neutrons which is known as an ‘alpha particle’. When the nucleus is split, two new nuclei of two different atoms are formed.
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Why don’t tortoises die from starvation and thirst when they are hibernating?
Monday, November 1st, 2010
To answer this question we should first ask ourselves why they need to eat and drink in the first place. Any animal, also a tortoise, needs food to provide it with energy. It needs energy to power its muscles, and keep its body temperature constant in the face of changes in the enviromental temperature.
It needs water because its body (like any animal) is to a great extent made up of water. But there is a continuous loss of water through sweating and the production of urine. Sweating contributes to cooling of the body, and urine will excrete some of the waste that is produced when the animal extracts energy from its food.
Tags: Biology, hibernation, tortoises
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