Why does the periodic table of elements look like it does?
August 15th, 2016 by Roger Darlington
At this time of year, when I have few work meetings, I like to attend short courses at the City Literary Institute in central London. So I recently attended a course on the periodic table.
What does the periodic table look like? Check it out here.
How many elements are there? When the Russian scientist Dmitri Mendeleev invented the periodic table in 1869, there were only 83 known elements. For a long time, the table consisted of 92 elements and, as I recall, that was the situation when I studied chemistry at school in the 1960s. Today we have identified 118 elements (four of them announced this year), although only 92 of them are naturally occurring on earth.
How are the elements grouped? They are organised organised according to their atomic number (the number of protons in an atom of the element) and then placed in 7 rows and 18 columns which are determined by the characteristics of the electrons in each of these atoms.
Now, when I was school (which admittedly was a long time go), we were taught that each atom consisted of a nucleus containing neutrons (no charge) and protons (positive charge) surrounded by electrons (negative charge) and the visual model of the atom showed the electrons as essentially the same size as neutrons and protons and moving in close, circular orbits around the nucleus, a bit like the planets orbiting the sun.
However, on this course our lecturer Gary Retallick painted a more sophisticated picture.
- First, there is a common analogy about the structure of an atom in which the nucleus is a fly in the centre of a sports stadium and the electrons are tiny, tiny gnats circling the stadium, so most of the atom is ’empty’.
- Second, electrons are so much smaller than a proton – about 1/1800 of the size.
- Third, electrons do not go round in neat circular orbits but, because of probability theory, more in the form of ‘clouds’.
- Fourth, not all electrons in any given atom are in the same orbit or ‘cloud’ – there are four energy levels (electrons can jump or fall between these) and each energy level can host a different maximum number of electrons – 2 in level one, 8 in level 2, 18 in level 3, 32 in level 4.
The combination of the atomic number and the deployment of elections in a given atom determines its physical and chemical characteristics and where it is located in the periodic table.
So, now you know.
Posted in Science & technology | Comments (2)
Why is it Team GB and not Team UK?
August 14th, 2016 by Roger Darlington
It’s been ‘super Sunday’ today for the British in the Olympic Games in Rio de Janeiro with the nation storming into second place in the medal table. But why are our competitors called Team GB and not Team UK? Surely Northern Ireland should not be missed out?
If only it was that simple. Technically our guys should be called Team Great Britain, Northern Ireland, Isle of Man, Channel Islands and UK Overseas Territories – as explained here.
Posted in British current affairs | Comments (0)
A review of the film “Son Of A Gun”
August 14th, 2016 by Roger Darlington
Australian filmmakers rarely try to make a crime thriller movie for the international market, but “Son Of A Gun” is an effort that is modestly successful. You can read my review here.
Posted in Cultural issues | Comments (0)
Word of the day: Bildungsroman
August 14th, 2016 by Roger Darlington
I came across this word for the first time as a comment on “My Brilliant Friend”, the first of the four Neapolitan novels by Italian writer Elena Ferrante. My summer project is to read the whole series.
I learned that the German word is a term of literary criticism referring to a novel of formation, education or coming-of-age.
Posted in Cultural issues | Comments (0)
How long would you like to live? Welcome to the Blue Zone …
August 13th, 2016 by Roger Darlington
“Four areas of the world have been designated as Blue Zones by scientists: Okinawa island in Japan, parts of central-eastern Sardinia, the Nicoya peninsula in northwestern Costa Rica, and the Greek island of Ikaria.
Certain traits link most of these areas, where exceptional longevity has been proven. First, most of the populations have been isolated for long periods due to their geography or other reasons, which in some cases led to inbreeding between distant family members, possibly helping certain genetic variants that favour longevity to be passed on from generation to generation.
The insularity of these communities could explain some delays in socio-economic development, researchers have found, making them relatively poorer than other nearby communities and delaying the onset of capitalism. Other similar characteristics include high quality food (though not necessarily abundant), physically-active lifestyles, and a prevailing attitude of collectivist rather than individualistic thinking. The latter, in turn, has limited the onset of high stress levels in the communities, researchers said. Finally, the four communities all exhibit strong social cohesion, a fact that potentially allows older people to still feel like they are an important part of society.
Gianni Pes, the Sardinian scientist who helped coin the term Blue Zone, is not convinced there is any such thing as a “longevity gene” that sets the populations apart. For one, there are genetic differences between the populations of the 14 towns that comprise the Sardinian Blue Zone, suggesting other factors – like environment and diet – may play a bigger role than just genetics.”
This is an extract from a feature in today’s “Guardian” newspaper looking ay why certain parts of the world have clusters of people who live exceptionally long lives. There are all sorts of theories and the latest approach to the mystery involves trying to identify a specific gene.
Posted in Science & technology | Comments (1)
My heart bleeds for the people of Aleppo
August 12th, 2016 by Roger Darlington
Just a couple of weeks before the outbreak of the civil war in Syria, we visited the country for a holiday. The Arab Spring had engulfed Tunisia, Libya and Egypt but, on the surface, all seems quiet in Syria.
Every time I see a news item about the situation now in Syria, I remember our visit and my heart bleeds for its people. Currently the conflict in Aleppo – Syria’s largest city – is especially fraught and tragic. What did it used to be like there before the war? You can read my travel notes here.
Posted in World current affairs | Comments (0)
As if the Brexit decision wasn’t bad enough, now tea sales have fallen
August 11th, 2016 by Roger Darlington
We can’t blame younger people for the referendum decision – apparently most of them voted for the UK to remain in the European Union. But it seems that we can blame them for the fall in sales of teabags – they drink less tea than older people.
In a short feature in today’s “Guardian” newspaper, it states:
“It is a problem that has been brewing for some time: sales of ordinary teabags have been falling for the last five years, with a 14% drop between 2013 and 2015. Now, according to the latest market research, teabag sales are due to plummet even further – by 5% this year to £614m.
The problem, say researchers, is being caused by younger people having fewer brews; while a third of 55- to 64-year-olds choose a cuppa more than five times a day, only 16% of 16- to 34-year-olds do the same. And the generational divide doesn’t stop there. Green tea sales have shot up by 39% in the past two years, a trend led by younger drinkers.”
As a moderate in all things, when I’m at home, I tend to drink coffee in the morning and early afternoon and then switch to tea for the late afternoon and evening (which also includes a glass of red wine). What about you?
Posted in British current affairs | Comments (0)
U.S. presidential election (31): what about the other candidates?
August 10th, 2016 by Roger Darlington
I suppose that either Hillary Clinton or (perish the thought) Donald Trump will be the next president of the United States. But these are very strange times politically, so who knows? However, there are other candidates for the White House.
There is the Libertarian Party candidate Gary Johnson who is currently polling around 8% – more information here.
Then there is the Green Party candidate Jill Stein who is presently polling about 4% – more information here.
Now there is a guy called Evan McMullin who is a conservative independent – more information here.
If any of these challengers wants to appear with Clinton and Trump at the scheduled three debates between presidential candidates, he or she has be polling at least 15%. The venues have been warned to be ready just in case – see here.
Posted in American current affairs | Comments (0)
Was there really only one Renaissance?
August 9th, 2016 by Roger Darlington
I recently read a book called “Age Of Discovery” written by Ian Goldin & Chris Kutarna. This impressive and inspiring work is sub-titled “”Navigating The Risks And Rewards Of Our New Renaissance”. The theme of the book is that, since around 1990, we have been living in a time which is in effect a New Renaissance and we should learn some of the lessons from the original Renaissance of 1450-1550.
However, in first chapter of the book, the authors argue that renaissances can be you found in every civilisation. As well as the European Renaissance, they instance:
- The Mayan Classic Period of 300-900
- The early centuries of Korea’s Choson Dynasty (1392-1897)
- The Islamic Golden Age from 750-1260
- China’s Tang Dynasty of 618-907
- India’s Gupta Empire of 320-550
- The Mughal Empire under Akbar the Great (1556-1605)
We should avoid adopting a superior Western-centric view of history and appreciate that many parts of the world have exhibited periods of great cultural and technological flourishing.
Posted in History | Comments (0)
A review of the impressive book “Age Of Discovery”
August 8th, 2016 by Roger Darlington
There are not many books that are so wide-ranging in subject matter and optimistic about the present and future of humankind as “Age Of Discovery”. It argues that, for most people in most places on the globe, this is the best time to be alive in the whole of human history. You can read my review here.
Posted in World current affairs | Comments (0)