Study Modules XII Chemistry 2017
... 7. The electrical conductivity of a metal decreases with rise in temperature while that of a semiconductor increases.Explain. In metals with increase of temperature, the kernels start vibrating and thus offer resistance to the flow of electrons.Hence conductivity decreases. In case of semiconductors ...
... 7. The electrical conductivity of a metal decreases with rise in temperature while that of a semiconductor increases.Explain. In metals with increase of temperature, the kernels start vibrating and thus offer resistance to the flow of electrons.Hence conductivity decreases. In case of semiconductors ...
oxidation–reduction reaction
... compound is the number of electrons lost or gained by the atom when it forms ions. • Oxidation numbers are tools that scientists use in written chemical equations to help them keep track of the movement of electrons in a redox reaction. ...
... compound is the number of electrons lost or gained by the atom when it forms ions. • Oxidation numbers are tools that scientists use in written chemical equations to help them keep track of the movement of electrons in a redox reaction. ...
Chemistry - Tumkur University
... Recapitulation of s- and p-Block Elements Periodicity in s- and p-block elements with respect to electronic configuration, atomic and ionic size, ionization enthalpy, electronegativity (Pauling, Mulliken, and Alfred-Rochow scales).Allotropy in C, S, and P. Inert pair effect, diagonal relationship an ...
... Recapitulation of s- and p-Block Elements Periodicity in s- and p-block elements with respect to electronic configuration, atomic and ionic size, ionization enthalpy, electronegativity (Pauling, Mulliken, and Alfred-Rochow scales).Allotropy in C, S, and P. Inert pair effect, diagonal relationship an ...
Unit 1 Section 4 - Atomic Structure PPT
... Rutherford’s model has some limitations It did not explain the chemical properties of the elements It did not address the electrons • What are electrons doing? – How are they arranged & how do they move? ...
... Rutherford’s model has some limitations It did not explain the chemical properties of the elements It did not address the electrons • What are electrons doing? – How are they arranged & how do they move? ...
Chapter 3
... number and the same number of protons. Atoms do not necessarily have the same number of neutrons. • Atoms of the same element that have different numbers of neutrons are called isotopes. • One standard method of identifying isotopes is to write the mass number with a hyphen after the name of an elem ...
... number and the same number of protons. Atoms do not necessarily have the same number of neutrons. • Atoms of the same element that have different numbers of neutrons are called isotopes. • One standard method of identifying isotopes is to write the mass number with a hyphen after the name of an elem ...
Calculations with Chemical Formulas and Equations
... Calculating Empirical Formulas The compound para-aminobenzoic acid (you may have seen it listed as PABA on your bottle of sunscreen) is composed of carbon (61.31%), hydrogen (5.14%), nitrogen (10.21%), and oxygen (23.33%). Find the empirical formula of PABA. ...
... Calculating Empirical Formulas The compound para-aminobenzoic acid (you may have seen it listed as PABA on your bottle of sunscreen) is composed of carbon (61.31%), hydrogen (5.14%), nitrogen (10.21%), and oxygen (23.33%). Find the empirical formula of PABA. ...
One Hundred Years of the Bohr Atom
... our thinking consists in a comparison of different domains of experience, so that the one can make the other clearer for us. All our knowledge, the spontaneous as well as the scientific, is therefore full of analogies. When thinking proceeds to a new task, it does not take up quite new means and way ...
... our thinking consists in a comparison of different domains of experience, so that the one can make the other clearer for us. All our knowledge, the spontaneous as well as the scientific, is therefore full of analogies. When thinking proceeds to a new task, it does not take up quite new means and way ...
Quarter 1
... 1. The average atomic mass of Chlorine is 35.453 amu. The isotopes of Chlorine are Chlorine35 and Chlorine-37. Determine which isotope will be found in greatest abundance given the atomic mass. Answer: Chlorine exists as two common isotopes. Chlorine-35 has an atomic mass of about 35 amu, Chlorine-3 ...
... 1. The average atomic mass of Chlorine is 35.453 amu. The isotopes of Chlorine are Chlorine35 and Chlorine-37. Determine which isotope will be found in greatest abundance given the atomic mass. Answer: Chlorine exists as two common isotopes. Chlorine-35 has an atomic mass of about 35 amu, Chlorine-3 ...
Chapter 3 Atomic Structure
... John Dalton’s Atomic Theory J.J. Thompson’s Atomic Theory Ernest Rutherford’s Atomic Theory The Physics of Energy Niels Bohr’s Atomic Theory. ...
... John Dalton’s Atomic Theory J.J. Thompson’s Atomic Theory Ernest Rutherford’s Atomic Theory The Physics of Energy Niels Bohr’s Atomic Theory. ...
Challenge Problems
... for these elements today are very different from their accepted atomic masses at the time Döbereiner made his observations. Döbereiner also observed that strontium, calcium, and barium showed a gradual gradation in their properties, with the values of some of strontium’s properties being about midwa ...
... for these elements today are very different from their accepted atomic masses at the time Döbereiner made his observations. Döbereiner also observed that strontium, calcium, and barium showed a gradual gradation in their properties, with the values of some of strontium’s properties being about midwa ...
Chemistry Senior External Syllabus 1998
... In order to elaborate on the meaning of the general objectives for candidates, more specific objectives have been identified. These more specific objectives are further elaborated upon through dot-pointed outcomes which contain examples. Whilst the general objectives, specific objectives and dot-poi ...
... In order to elaborate on the meaning of the general objectives for candidates, more specific objectives have been identified. These more specific objectives are further elaborated upon through dot-pointed outcomes which contain examples. Whilst the general objectives, specific objectives and dot-poi ...
levels of comprehension of scientific prose: the role of text variables
... presence of a similar positive charge in the atoms of gold. These additions were necessary to understand the existence of a positive charge concentrated in a very small area within the atom, one of the most important conclusions gained from Rutherford’s experiment. We did not elaborate on certain id ...
... presence of a similar positive charge in the atoms of gold. These additions were necessary to understand the existence of a positive charge concentrated in a very small area within the atom, one of the most important conclusions gained from Rutherford’s experiment. We did not elaborate on certain id ...
Ch. 11-12 Supplements
... 3) a. Write the balanced equation for the reaction of aqueous sulfuric acid, H2SO4, and solid aluminum hydroxide, Al(OH)3 forming liquid water and aqueous aluminum sulfate, Al2(SO4)3. If 30.0 grams of sulfuric acid and 25.0 grams of aluminum hydroxide react… b. How many grams of each product will b ...
... 3) a. Write the balanced equation for the reaction of aqueous sulfuric acid, H2SO4, and solid aluminum hydroxide, Al(OH)3 forming liquid water and aqueous aluminum sulfate, Al2(SO4)3. If 30.0 grams of sulfuric acid and 25.0 grams of aluminum hydroxide react… b. How many grams of each product will b ...
semester i - Pt. Ravishankar Shukla University
... Vector quantities and their properties Complex numbers and Coordinate transformation. Differential and Integral Calculus, Basis rules of differentiation and Integration Applications. B. The Schrodinger equation and postulates of quantum mechanics. Discussion of solutions of the Schrodinger equation ...
... Vector quantities and their properties Complex numbers and Coordinate transformation. Differential and Integral Calculus, Basis rules of differentiation and Integration Applications. B. The Schrodinger equation and postulates of quantum mechanics. Discussion of solutions of the Schrodinger equation ...
Topic 1: Quantitative chemistry (12
... Students should be able to draw an energy level diagram, show transitions between different energy levels and recognize that the lines in a line spectrum are directly related to these differences. An understanding of convergence is expected. Series should be considered in the ultraviolet, visible an ...
... Students should be able to draw an energy level diagram, show transitions between different energy levels and recognize that the lines in a line spectrum are directly related to these differences. An understanding of convergence is expected. Series should be considered in the ultraviolet, visible an ...
formula writing and nomenclature of inorganic - Parkway C-2
... +1, while each chlorine atom has gained one electron and is assigned an oxidation number of -1. The two ions are held together as a result of their opposite charges in what is called an ionic bond. As a second example, consider the formation of water from hydrogen and oxygen: 2 H2 + O2 → 2 H2O In th ...
... +1, while each chlorine atom has gained one electron and is assigned an oxidation number of -1. The two ions are held together as a result of their opposite charges in what is called an ionic bond. As a second example, consider the formation of water from hydrogen and oxygen: 2 H2 + O2 → 2 H2O In th ...
Topic 1: Quantitative chemistry (12
... Students should be able to draw an energy level diagram, show transitions between different energy levels and recognize that the lines in a line spectrum are directly related to these differences. An understanding of convergence is expected. Series should be considered in the ultraviolet, visible an ...
... Students should be able to draw an energy level diagram, show transitions between different energy levels and recognize that the lines in a line spectrum are directly related to these differences. An understanding of convergence is expected. Series should be considered in the ultraviolet, visible an ...
Physical Sciences Grade 10 Term 2
... tube and fills the test tube up to the ¾ mark with water. The contents of the test tube are then shaken vigorously to dissolve the chemicals, use a rubber stopper to close the test tube before shaking it. If possible measure the mass of all the test tubes with their contents and record this mass. To ...
... tube and fills the test tube up to the ¾ mark with water. The contents of the test tube are then shaken vigorously to dissolve the chemicals, use a rubber stopper to close the test tube before shaking it. If possible measure the mass of all the test tubes with their contents and record this mass. To ...
Stoichiometric Conversions
... gas, the two will combust and form carbon dioxide and water CH4 + 2O2 CO2 + 2H2O How many moles of H2O will be formed when 28.0 g of methane combusts? ...
... gas, the two will combust and form carbon dioxide and water CH4 + 2O2 CO2 + 2H2O How many moles of H2O will be formed when 28.0 g of methane combusts? ...
Part II
... Frequency of collisions is about 5 x 109 sec-1 / atm at 298 K. 3) Molecules can react with each other when they collide ! 4) The rate at which collisions occur defines the maximum rate at which two molecules can react with each other. The maximum (“Gas Kinetic”) rate coefficient for a bimolecular re ...
... Frequency of collisions is about 5 x 109 sec-1 / atm at 298 K. 3) Molecules can react with each other when they collide ! 4) The rate at which collisions occur defines the maximum rate at which two molecules can react with each other. The maximum (“Gas Kinetic”) rate coefficient for a bimolecular re ...
Chemical Reactions - 2012 Book Archive
... (1 × 15.9994 g), its molar mass is 46.069 g/mol. Similarly, the formula mass of calcium phosphate [Ca3(PO4)2] is 310.177 amu, so its molar mass is 310.177 g/mol. This is the mass of calcium phosphate that contains 6.022 × 1023 formula units. Figure 3.1 "Samples of 1 Mol of Some Common Substances" sh ...
... (1 × 15.9994 g), its molar mass is 46.069 g/mol. Similarly, the formula mass of calcium phosphate [Ca3(PO4)2] is 310.177 amu, so its molar mass is 310.177 g/mol. This is the mass of calcium phosphate that contains 6.022 × 1023 formula units. Figure 3.1 "Samples of 1 Mol of Some Common Substances" sh ...
chemistry - Textbooks Online
... Where has chemistry come from ? Throughout the history of the human race, people have struggled to make sense of the world around them. Through the branch of science we call chemistry we have gained an understanding of the matter which makes up our world and of the interactions between particles on ...
... Where has chemistry come from ? Throughout the history of the human race, people have struggled to make sense of the world around them. Through the branch of science we call chemistry we have gained an understanding of the matter which makes up our world and of the interactions between particles on ...
History of molecular theory
In chemistry, the history of molecular theory traces the origins of the concept or idea of the existence of strong chemical bonds between two or more atoms.The modern concept of molecules can be traced back towards pre-scientific Greek philosophers such as Leucippus who argued that all the universe is composed of atoms and voids. Circa 450 BC Empedocles imagined fundamental elements (fire (20px), earth (20px), air (20px), and water (20px)) and ""forces"" of attraction and repulsion allowing the elements to interact. Prior to this, Heraclitus had claimed that fire or change was fundamental to our existence, created through the combination of opposite properties. In the Timaeus, Plato, following Pythagoras, considered mathematical entities such as number, point, line and triangle as the fundamental building blocks or elements of this ephemeral world, and considered the four elements of fire, air, water and earth as states of substances through which the true mathematical principles or elements would pass. A fifth element, the incorruptible quintessence aether, was considered to be the fundamental building block of the heavenly bodies. The viewpoint of Leucippus and Empedocles, along with the aether, was accepted by Aristotle and passed to medieval and renaissance Europe. A modern conceptualization of molecules began to develop in the 19th century along with experimental evidence for pure chemical elements and how individual atoms of different chemical substances such as hydrogen and oxygen can combine to form chemically stable molecules such as water molecules.