The Periodic Table
Gbogbo ọrọ náà
Hanging on the wall of every chemistry laboratory is a chart that looks, at first glance, like a storage rack for about 118 facts. It is nothing of the sort. It is the most powerful prediction machine that chemistry has ever produced. Hand a chemist an element they have never worked with, tell them only where it sits on that chart, and they will tell you whether it is a metal, roughly how it will behave with water, and what the formula of its oxide is likely to be.
This lesson takes the chart apart and shows you the machinery. You will find out why the columns exist at all, what is actually repeating when we call the table periodic, how to read the four lines printed inside every box on the copy this course gives you, and how a professor in St Petersburg was able to describe elements that nobody had yet laid eyes on. You will finish with the strangest column of the lot: a little under one percent of the air you are breathing, made of atoms so content with their own electrons that for a century chemists believed they could form no compounds at all.
Ebumnobi
- The periodic table is arranged in order of atomic (proton) number. Elements with similar properties are in columns, known as groups. The table is called a periodic table because similar properties occur at regular intervals. Students should know that the current periodic table is based on the work of Mendeleev.
- Elements in the same group in the periodic table have the same number of electrons in their highest energy level (outer electrons) and this gives them similar chemical properties. Students should know that basing the periodic table on groups of elements with similar properties has allowed for the prediction of elements which were still to be discovered.
- The elements in Group 0 of the periodic table are called the noble gases. They are unreactive because their atoms have stable arrangements of electrons. Students should know that the noble gases have eight electrons in their outer energy level, except for helium, which has only two electrons.
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Akwụkwọ Ọmụmụ
Ndetu Nkuzi Zuru Ezu di na Ngwa Green Bridge
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Nnyocha Ọmụmụ
Ekele diri gi maka imecha ihe karịrị na The Periodic Table. Ugbu a na ị na-enyochakwa isi echiche na echiche ndị dị mkpa, ọ bụ oge iji nwalee ihe ị ma. Ngwa a na-enye ụdị ajụjụ ọmụmụ dị iche iche emebere iji kwado nghọta gị wee nyere gị aka ịmata otú ị ghọtara ihe ndị a kụziri.
Ị ga-ahụ ngwakọta nke ụdị ajụjụ dị iche iche, gụnyere ajụjụ chọrọ ịhọrọ otu n’ime ọtụtụ azịza, ajụjụ chọrọ mkpirisi azịza, na ajụjụ ede ede. A na-arụpụta ajụjụ ọ bụla nke ọma iji nwalee akụkụ dị iche iche nke ihe ọmụma gị na nkà nke ịtụgharị uche.
Jiri akụkụ a nke nyocha ka ohere iji kụziere ihe ị matara banyere isiokwu ahụ ma chọpụta ebe ọ bụla ị nwere ike ịchọ ọmụmụ ihe ọzọ. Ekwela ka nsogbu ọ bụla ị na-eche ihu mee ka ị daa mba; kama, lee ha anya dị ka ohere maka ịzụlite onwe gị na imeziwanye.
- The elements in the modern periodic table are arranged in order of increasing: A. mass number B. atomic number C. number of neutrons D. relative atomic mass Answer: B
- An atom of an element has the electron arrangement 2,8,8,1. In which group of the periodic table is this element found? A. Group 0 B. Group 1 C. Group 2 D. Group 7 Answer: B
- Which statement must be true of two elements found in the same group? A. They have the same number of protons in their atoms. B. They have the same number of occupied energy levels. C. They have the same number of electrons in their highest occupied energy level. D. They have the same relative atomic mass. Answer: C
- Why are the elements in Group 0 unreactive? A. Their atoms are much smaller than other atoms. B. Their atoms already have a stable arrangement of electrons. C. Their atoms contain no electrons in the outer energy level. D. Their atoms have more neutrons than protons. Answer: B
- Which statement about the outer energy level of the noble gases is correct? A. Every noble gas has eight electrons in it. B. Every noble gas has two electrons in it. C. Helium has two electrons in it and the other noble gases have eight. D. Helium has eight electrons in it and the other noble gases have two. Answer: C
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Meecha Ajụjụ Ule Ọmarịcha
Ị chọrọ ime ajụjụ ule ọmarịcha gbasara The Periodic Table? Budata ngwa Green Bridge CBT iji nweta ajụjụ ule ọmarịcha na nyocha zuru ezu gbasara isiokwu a.
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