This month we learnt about chemical bonding, pH values, atomic structure and the periodic table simultaneously. I think that it is good to learn different topics at the same time as it is more interesting. What I like the most is chemical bonding because it has got to do with writing and balancing equations and also has got to do with the atomic structure. I also think that the periodic table is interesting as there are many types of elements and countless compounds can be formed. I wonder if there are more elements that haven't been founded yet. I hope we can cover more in February.
Shao Xuan
(Post #4)
Thursday, February 10, 2011
Online Lesson Task 2: Periodic Table
Full Name: Henry Gwyn Jeffreys Moseley
Place of Birth: Weymouth, Dorset
Date of Birth and Death: 23 November 1887 and 10 August 1915
Work Done: He had justified physical laws of the previous empirical and chemical concept of the atomic number and justified many concepts in chemistry by sorting the chemical elements of the Periodic Table of the Elements in a quite logical order based on their physics. Moseley showed that there were gaps in the atomic number sequence at numbers 43, 61, 72, and 75, and gave very strong evidence that there were no other gaps in the Periodic Table between the elements aluminium (atomic number 13) and gold (atomic number 79).
His Contribution: Moseley's discovery showed that atomic numbers were not arbitrarily assigned, but rather, they have a strong physical basis. Moseley redefined the idea of atomic numbers from its previous status as an ad hoc numerical tag to help sorting the elements, in particular in the Periodic Table, into a real and objective whole-number quantity that was experimentally measurable. His experimental set of data showed that with a positively-charged nucleus surrounded by negatively-charged electrons, the atomic number is understood to be the exactly physical number of positive charges (later discovered and called protons) in the central atomic nuclei of the elements.
Technology Available: X-ray Spectrometers
Relevance to Today: He gave very strong evidence that there were no other gaps in the Periodic Table between the elements aluminium (atomic number 13) and gold (atomic number 79). Also, he stated that a positively-charged nucleus surrounded by negatively-charged electrons in which the atomic number is understood to be the exactly physical number of positive charges, which we use now.
Source: http://en.wikipedia.org/wiki/Henry_Moseley
Shao Xuan
(Post #3)
Place of Birth: Weymouth, Dorset
Date of Birth and Death: 23 November 1887 and 10 August 1915
Work Done: He had justified physical laws of the previous empirical and chemical concept of the atomic number and justified many concepts in chemistry by sorting the chemical elements of the Periodic Table of the Elements in a quite logical order based on their physics. Moseley showed that there were gaps in the atomic number sequence at numbers 43, 61, 72, and 75, and gave very strong evidence that there were no other gaps in the Periodic Table between the elements aluminium (atomic number 13) and gold (atomic number 79).
His Contribution: Moseley's discovery showed that atomic numbers were not arbitrarily assigned, but rather, they have a strong physical basis. Moseley redefined the idea of atomic numbers from its previous status as an ad hoc numerical tag to help sorting the elements, in particular in the Periodic Table, into a real and objective whole-number quantity that was experimentally measurable. His experimental set of data showed that with a positively-charged nucleus surrounded by negatively-charged electrons, the atomic number is understood to be the exactly physical number of positive charges (later discovered and called protons) in the central atomic nuclei of the elements.
Technology Available: X-ray Spectrometers
Relevance to Today: He gave very strong evidence that there were no other gaps in the Periodic Table between the elements aluminium (atomic number 13) and gold (atomic number 79). Also, he stated that a positively-charged nucleus surrounded by negatively-charged electrons in which the atomic number is understood to be the exactly physical number of positive charges, which we use now.
Source: http://en.wikipedia.org/wiki/Henry_Moseley
Shao Xuan
(Post #3)
Monday, February 7, 2011
Online Lesson Task 1: Periodic Table
i) Scientists have created all the elements beyond element 92. Find out how they have been made.
They are called transuranium elements. They are formed when a lighter neutron is charged into a heavier atom using a cyclotron invented by Ernest Lawrence in the 1930s. Thus their atomic number became bigger and thus form the man-made transuranium elements.
Source: http://science.jrank.org/pages/2410/Element-Transuranium.html
ii) It is said that the stars are the ‘element factories of the universe’, that is, stars make the elements. Do some research and find out how the stars make elements.
The stars are actually big groups of gases pulled together by their own gravity. They start off with the fundamental hydrogen elements, but then, at extreme temperatures, start to nuclear fuse, which results in helium, followed by other heavier atoms.
Source: http://imagine.gsfc.nasa.gov/docs/science/know_l2/stars.html
iii) Choose an element and research the following information about it:
- When it was discovered
- by whom it was discovered
- how it is found in nature
- its properties and uses.
Tungsten (W)
Discovered in 1783 by Fausto and Juan Jose de Elhuyar.
Tungsten is never found as a free element in nature. It comes in compounds such as scheelite or iron manganese tungstate.
It is added to other metals to make it a stronger alloy. It is also used importantly in lightbulbs.
Source: http://www.chemicalelements.com/elements/w.html
Source: http://www.chemistryexplained.com/elements/T-Z/Tungsten.html
Shao Xuan
(Post #2)
They are called transuranium elements. They are formed when a lighter neutron is charged into a heavier atom using a cyclotron invented by Ernest Lawrence in the 1930s. Thus their atomic number became bigger and thus form the man-made transuranium elements.
Source: http://science.jrank.org/pages/2410/Element-Transuranium.html
ii) It is said that the stars are the ‘element factories of the universe’, that is, stars make the elements. Do some research and find out how the stars make elements.
The stars are actually big groups of gases pulled together by their own gravity. They start off with the fundamental hydrogen elements, but then, at extreme temperatures, start to nuclear fuse, which results in helium, followed by other heavier atoms.
Source: http://imagine.gsfc.nasa.gov/docs/science/know_l2/stars.html
iii) Choose an element and research the following information about it:
- When it was discovered
- by whom it was discovered
- how it is found in nature
- its properties and uses.
Tungsten (W)
Discovered in 1783 by Fausto and Juan Jose de Elhuyar.
Tungsten is never found as a free element in nature. It comes in compounds such as scheelite or iron manganese tungstate.
It is added to other metals to make it a stronger alloy. It is also used importantly in lightbulbs.
Source: http://www.chemicalelements.com/elements/w.html
Source: http://www.chemistryexplained.com/elements/T-Z/Tungsten.html
Shao Xuan
(Post #2)
Introduction
This will be the first post of my Science ePortfolio. Well I have upgraded from Prezi to Blogger, and will update frequently what I have learnt over the term.
Shao Xuan
(Post #1)
Shao Xuan
(Post #1)
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