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Lewis Dot Structure For Silicon

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Last Updated: 22 October 2020

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General | Latest Info

Silicon has 23 isotopes with mass numbers ranging from 22 to 44. Remember, isotopes of element have the same number of protons, but different amounts of neutrons. Mass numbers tell how many protons and neutrons an isotope has. There are three naturally occurring isotopes of silicon and twenty isotopes that are artificial.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Silicon Discovery

Properties and Characteristics of Silicon

Atomic mass28.085 atomic mass units
Atomic weight28.085
Mass number28
Molar mass/molecular weight28.085 g/mol
Color/appearanceSilvery
LusterBlue-gray metallic sheen
TextureHard
MalleabilityNo
DuctilityNo
Melting point/freezing point1414C, 2577F
Boiling point3265C, 5909F
Density2.3296 g cm -3
State of matter at room temperature (normal phase)Solid
Hardness (Vickers scale)9630.1303 MPa
Electrical conductivity1000 S/m
Thermal Conductivity150 W/(m K)
Dielectric constant/relative permittivity11.7
Specific heat capacity0.7 J g -1o C -1
Resistivity6.4 x 10 2 ohm-m
Youngs modulus140-180 GPa
Tensile strength165-180 MPa
Refractive index3.9766
FlammabilityYes
Oxidation states/ionic charge+4, +2, -4

Silica has been used by human civilization for a long time. Some tools made by first humans had silica flints. In fact, name is derived from the Latin word for flint, silicis. Chemists weren't really interested in the structure of silica until Antoine Lavoisier proposed that it was an element in 1787. In the early 1800s, another chemist, Sir Humphry Davy, who was famous at the time for finding elements, proclaimed that silica was in fact a compound, made up of more than one element. However, his tried and true method of element discovery using electrolysis didn't yield elements from silica. Swedish chemist Jons Jacob Berzelius gets credit for discovering Silicon. He isolated element by heating potassium metal with potassium fluorosilicate in 1824.

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Table 1: Properties of Silicon

SymbolSi
Atomic Number14
Group14 ( Carbon Family )
Electron Configuration3s 2 3p 2
Atomic Weight28.0855 g
Density2.57 g/mL
Melting Point1414 o C
Boiling Point3265 o C
Oxidation States4, 3, 2, 1, -1, -2, -3, -4
Electronegativity1.90
Stable Isotopes28 Si 29 Si 30 Si
* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Silicon Versus Carbon

Table 1: Properties of Silicon

SymbolSi
Atomic Number14
Group14 ( Carbon Family )
Electron Configuration3s 2 3p 2
Atomic Weight28.0855 g
Density2.57 g/mL
Melting Point1414 o C
Boiling Point3265 o C
Oxidation States4, 3, 2, 1, -1, -2, -3, -4
Electronegativity1.90
Stable Isotopes28 Si 29 Si 30 Si

Silicon is in group 14 and period 3 of the periodic table. Remember, groups are vertical columns and rows are periods. Elements in groups share similar properties. Silicon is particularly interesting to scientists because it shares so many similar traits with Carbon. Both elements are found in group 14, which means they have four valence electrons, electrons that are responsible for forming chemical bonds. This means that carbon and silicon can form similar molecules. For example, you are probably familiar with carbon dioxide, which leaves your body when you exhale. There is also silicon form of that molecule called Silicon dioxide, which is what makes up the sand beneath your feet on the beach. Okay, so, big deal. Carbon and Silicon are really similar. What does that actually mean? Well, carbon is building block of life on earth. Humans are a big bunch of carbon molecules that interact in symphony to create life. Scientists and science fiction writers have often proposed that if life exists on other planets, it very well be based on Silicon instead of Carbon because of their similarities.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Properties of Silicon

Table 1: Properties of Silicon

SymbolSi
Atomic Number14
Group14 ( Carbon Family )
Electron Configuration3s 2 3p 2
Atomic Weight28.0855 g
Density2.57 g/mL
Melting Point1414 o C
Boiling Point3265 o C
Oxidation States4, 3, 2, 1, -1, -2, -3, -4
Electronegativity1.90
Stable Isotopes28 Si 29 Si 30 Si

Silicon is a crystalline semi - metal or metalloid. One of its forms is shiny, grey and very brittle. It is group 14 element in the same periodic group as Carbon, but chemically behaves distinctly from all of its group counterparts. Silicon shares the bonding versatility of Carbon, with its four valence electrons, but is otherwise a relatively inert element. However, under special conditions, Silicon can be made to be a good deal more reactive. Silicon exhibits metalloid properties, is able to expand its valence shell, and is able to be transformed into a semiconductor; distinguishing it from its periodic group members.

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* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Lesson Summary

Silica or silicon dioxide is a very prominent molecule that has atom silicon in it. Silica was used to make flints in ancient cultures, and the name silicon comes from the Latin word for flint. Antoine Lavoisier proposed that silica was an element, but Sir Humphry Davy believed it was compound. Jons Jacob Berzelius prove Davy correct by isolating elements in 1824. Silicon is in group 14 and period 3 of the periodic table and has four valence electrons in its Lewis structure. Four valence electrons mean that silicon can bond in a way similar to carbon. Because of this, scientists and science fiction writers have pondered that extraterrestrial life may be silicon - base. Silicon has Atomic number 14, which means it has 14 protons in its nucleus. It has the chemical symbol Si and is classified as a metalloid. It will react with bases and hydrofluoric acid, but no other acids. There are three natural isotopes of silicon and 20 artificial isotopes of silicon with mass numbers ranging from 22 to 44.


Lewis Structures for Polyatomic Ions

Lewis structure of ion is placed in brackets and its charge is written as superscript outside of the brackets, on upper right. The total number of electrons represented in the Lewis structure is equal to the sum of the number of valence electrons in each individual atom. Non - valence electrons are not represented in Lewis structures. After the total number of available electrons has been determine, electrons must be placed into structure. Lewis structures for polyatomic ions are drawn by the same methods that we have already learned. When counting electrons, negative ions should have extra electrons place in their Lewis structures; positive ions should have fewer electrons than uncharged molecule. When Lewis structure of ion is write, entire structure is placed in brackets, and charge is written as superscript on upper right, outside of brackets. For example, consider the ammonium ion, NH 4 +, which contains 9 - 1 = 8 electrons. One electron is subtracted because the entire molecule has + 1 charge.


Representing Valence Electrons in Lewis Symbols

We use Lewis symbols to describe valence electron configurations of atoms and monatomic ions. Lewis symbols consist of elemental symbols surrounded by one dot for each of its valence electrons: table below shows Lewis symbols for elements of the third period of the periodic table. Lewis symbols can also be used to illustrate formation of cations from atoms, as shown here for sodium and calcium: likewise, they can be used to show formation of anions from atoms, as shown here for chlorine and sulfur: following table demonstrates use of Lewis symbols to show transfer of electrons during formation of ionic compounds.


The Octet Rule

For very simple molecules and molecular ions, we can write Lewis structures by merely pairing up unpaired electrons on constituent atoms. See these examples: For more complicated molecules and molecular ions, it is helpful to follow the step - by - step procedure outlined here: determining total number of valence electrons. For cations, subtract one electron for each positive charge. For anions, add one electron for each negative charge. Draw skeleton structure of a molecule or ion, arranging atoms around the central atom. Connect each atom to the central atom with a single bond. Distribute remaining electrons as lone pairs on terminal atoms, completing octet around each atom. Place all remaining electrons on the central atom. Rearrange electrons OF outer atoms to make multiple bonds with central atom in order to obtain octets wherever possible. Let us determine Lewis structures OF, and as example in following this procedure: determine the total number OF valence electrons in molecule or ion. For molecule, we add the number OF valence electrons on each atom in molecule: SiH 4 Si: 4 valence electrons / atom 1 atom = 4 + H: 1 valence electron / atom 4 atoms = 4 = 8 valence electrons. For negative ion, we add the number OF valence electrons on atoms to the number OF negative charges on ion: CHO 2 - C: 4 valence electrons / atom 1 atom = 4 H: 1 valence electrons / atom 1 atom = 1 O: 6 valence electrons / atom 2 & atoms = 12 + 1 additional electron = 18 valence electrons For positive ion, such as, We add number OF valence electrons on atoms in ion and then subtract number OF positive charges on ion from total number OF valence electrons: NO + N: 5 valence electrons / atom 1 atom = 5 O: 6 valence electrons / atom 1 atom = 6 + - 1 electron = 10 valence electrons Since is neutral molecule, We simply add number OF valence electrons: OF 2 O: 6 valence electrons / atom 1 atom = 6 + F: 7 valence electrons / atom 2 atoms = 14 = 20 valence electrons Draw skeleton structure OF molecule or ion, arranging atoms around central atom and connecting each atom to central atom with single bond. When several arrangements OF atoms are possible, as For, we must use experimental evidence to choose the correct one. In general, less electronegative elements are more likely to be central atoms. In, less electronegative carbon atoms occupy central position with oxygen and hydrogen atoms surrounding them. Other examples include In, In, and In. An exception is that hydrogen is almost never the central atom. Like most electronegative element,ss fluorine also cannot be central atom. Distribute remaining electrons as lone pairs on terminal atoms to complete their valence shells with octet OF electrons.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

Lewis Symbols of Monoatomic Elements

Table

BondBond Length
N-N1.47 A
N=N1.24 A
NN1.10 A

Thus far in this chapter, we have discussed various types of bonds that form between atoms and / or ions. In all cases, these bonds involve sharing or transfer of valence shell electrons between atoms. In this section, we will explore typical methods for depicting valence shell electrons and chemical bonds, namely Lewis symbols and Lewis Structures. Dalton knew of the experiments of French chemist Joseph Proust, who demonstrated that all samples of pure compound contain same elements in same proportion by mass. This statement is known as the law of Definite Proportions or law of constant composition. The suggestion that the numbers of atoms of elements in give compound always exist in the same ratio is consistent with these observations. For example, when different samples of isooctane are analyze, they are found to have a Carbon - to - hydrogen mass ratio of 5. 33: 1, as show In. It is worth noting that although all samples of a particular compound have the same mass ratio, converse is not true in general. That is, samples that have the same mass ratio are not necessarily the same substance. For example, there are many compounds other than isooctane that also have a Carbon - to - hydrogen mass ratio of 5. 33: 1. 00. Dalton also uses data from Proust, as well as results from his own experiments, to formulate another interesting law. The Law of Multiple Proportions states that when two elements react to form more than one compound, fixed mass of one element will react with masses of other elements in a ratio of small, whole numbers. For example, copper and chlorine can form green, crystalline solids with a mass ratio of 0. 558 g chlorine to 1 g copper, as well as brown crystalline solid with a mass ratio of 1. 116 g chlorine to 1 g copper. These ratios by themselves may not seem particularly interesting or informative; However, if we take the ratio of these ratios, we obtain a useful and possibly surprising result: small, whole - number ratio. {matheq}\frac{\frac{1.116 \text{ g Cl}}{1 \text{ g Cu}}}{\frac{0.558 \text{ g Cl}}{1 \text{ g Cu}}} = \frac{2}{1}{endmatheq} this can be explained by Atomic Theory if the copper - to - chlorine ratio in the brown compound is 1 copper atom to 2 chlorine atoms, and the ratio in the green compound is 1 copper atom to 1 chlorine atom. The ratio of chlorine atoms is therefore 2 to 1. The earliest recorded discussion of the basic structure of matter came from ancient Greek philosophers, scientists of their day. In the fifth century BC, Leucippus and Democritus argued that all matter was composed of small, finite particles that they called atomos, term derived from the Greek word for indivisible. They think of atoms as moving particles that differ in shape and size, and which could join together. Later, Aristotle and others came to the conclusion that matter consists of various combinations of four elementsfire, Earth, air, and water could be infinitely divide. Interestingly, these philosophers think about atoms and elements as philosophical concepts, but apparently never consider performing experiments to test their ideas.


Lewis Structures

We also use Lewis symbols to indicate the formation of covalent bonds, which are shown in Lewis structures, drawings that describe bonding in molecules and polyatomic ions. For example, when two chlorine atoms form chlorine molecule, they share one pair of electrons: Lewis structure indicates that each atom has three pairs of electrons that are not used in bonding and one share pair of electrons. Dash is sometimes used to indicate shared pair of electrons: single shared pair of electrons is called a single bond. Each atom interacts with eight valence electrons: six in lone pairs and two in single bond.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

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* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions.

* Please keep in mind that all text is machine-generated, we do not bear any responsibility, and you should always get advice from professionals before taking any actions

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