Lectures 14-15 - U of L Class Index
... The ΔEAH for an element in group 15 is slightly less negative than that for the element to its left. This is due to increased electronelectron repulsion when adding electrons into a half-full orbital. ...
... The ΔEAH for an element in group 15 is slightly less negative than that for the element to its left. This is due to increased electronelectron repulsion when adding electrons into a half-full orbital. ...
Sep 2
... Rutherford's nuclear model: 1. Most of atom's mass is in a tiny dense nucleus 2. Most of the volume is empty space, with tiny electrons around the nucleus 3. In a neutral atom, the number of protons equals the number of ...
... Rutherford's nuclear model: 1. Most of atom's mass is in a tiny dense nucleus 2. Most of the volume is empty space, with tiny electrons around the nucleus 3. In a neutral atom, the number of protons equals the number of ...
Slide 1
... - a given compound always contains the same elements in the same proportions by mass ...
... - a given compound always contains the same elements in the same proportions by mass ...
Periodic trends Tempura
... Mendeleev said that the properties of the elements are periodic if elements are arranged by increasing atomic mass. The use of mass was incorrect as Mendeleev found with the discovery of reversed pairs. Modern periodic law says the properties are periodic (and elements are in the same column if they ...
... Mendeleev said that the properties of the elements are periodic if elements are arranged by increasing atomic mass. The use of mass was incorrect as Mendeleev found with the discovery of reversed pairs. Modern periodic law says the properties are periodic (and elements are in the same column if they ...
Lecture 10
... •An element’s enthalpy of electronic attraction (ΔEAH) is the enthalpy change when a neutral atom in the gas phase acquires an extra electron in the lowest energy orbital available: •These values are negative for most elements, so an ‘increase’ in the ΔEAH is represented by a more negative number. A ...
... •An element’s enthalpy of electronic attraction (ΔEAH) is the enthalpy change when a neutral atom in the gas phase acquires an extra electron in the lowest energy orbital available: •These values are negative for most elements, so an ‘increase’ in the ΔEAH is represented by a more negative number. A ...
Periodic Table History & Organization
... In small atoms, e- are close to the nucleus where the attraction is stronger Why small jumps within each group? Stable e- configurations don’t want to lose e- ...
... In small atoms, e- are close to the nucleus where the attraction is stronger Why small jumps within each group? Stable e- configurations don’t want to lose e- ...
Chapter 4
... Introduction to Atoms • Development of atomic Theory – Dalton’s atomic theory: Dalton thought that atoms were like smooth, hard balls that could not be broken into smaller pieces. – Thomson’s model suggested atoms had negatively charged electrons embedded in a positive sphere – Rutherford’s model s ...
... Introduction to Atoms • Development of atomic Theory – Dalton’s atomic theory: Dalton thought that atoms were like smooth, hard balls that could not be broken into smaller pieces. – Thomson’s model suggested atoms had negatively charged electrons embedded in a positive sphere – Rutherford’s model s ...
Posttest answers - Aurora City Schools
... anyway. Also, there’s nothing like the Alien PT on the test, although you should be able to answer questions like that (e.g. which of the following has 3 valence electrons). Also, also I put some unused self-assessments and answer keys on SchoolPointe for you. They may all be fairly similar, but som ...
... anyway. Also, there’s nothing like the Alien PT on the test, although you should be able to answer questions like that (e.g. which of the following has 3 valence electrons). Also, also I put some unused self-assessments and answer keys on SchoolPointe for you. They may all be fairly similar, but som ...
C1.1 The fundamental ideas in chemistry
... When elements react, their atoms join with other atoms to form compounds. This involves giving, taking or sharing electrons to form ions or molecules. Compounds formed from metals and non-metals consist of ions. Compounds formed from nonmetals consist of molecules. In molecules the atoms are held to ...
... When elements react, their atoms join with other atoms to form compounds. This involves giving, taking or sharing electrons to form ions or molecules. Compounds formed from metals and non-metals consist of ions. Compounds formed from nonmetals consist of molecules. In molecules the atoms are held to ...
7th Grade Study Guide Test #1 – Jan. 28th Chapter 4.1: Introduction
... model of the atom. (Democritus, Dalton, Thompson, Rutherford and Bohr) 2. Identify the experiments the scientists above used to support their findings (Discharge cathode rays, gold foil experiment) 3. Determine who was responsible for: a. Determining that atoms are indivisible b. Atoms of the same e ...
... model of the atom. (Democritus, Dalton, Thompson, Rutherford and Bohr) 2. Identify the experiments the scientists above used to support their findings (Discharge cathode rays, gold foil experiment) 3. Determine who was responsible for: a. Determining that atoms are indivisible b. Atoms of the same e ...
Unit 3 Study Guide
... Is this still true today? Explain. No, it is not true. In Dalton’s time technology for splitting atoms was not yet developed. 2. According to Dalton’s theory all atoms of the same element are identical in mass, size and properties. Is this still true today? Explain. Part of it is true. Atoms of the ...
... Is this still true today? Explain. No, it is not true. In Dalton’s time technology for splitting atoms was not yet developed. 2. According to Dalton’s theory all atoms of the same element are identical in mass, size and properties. Is this still true today? Explain. Part of it is true. Atoms of the ...
MORE ABOUT PROTONS, NEUTRONS AND ELECTRONS
... Using the periodic table again, we can see what makes elements of different atoms unique - it is not the mass (note that cobalt and nickel both have the same Ar, rather it is the number of protons that they have. Atoms are arranged in the periodic table according to the number of protons present. Th ...
... Using the periodic table again, we can see what makes elements of different atoms unique - it is not the mass (note that cobalt and nickel both have the same Ar, rather it is the number of protons that they have. Atoms are arranged in the periodic table according to the number of protons present. Th ...
mass of an atom - CHM101-02
... Isotopes: Atoms with the same # of p+s and e-s but different # of n's. They have the same chemical properties except that they are different in mass ...
... Isotopes: Atoms with the same # of p+s and e-s but different # of n's. They have the same chemical properties except that they are different in mass ...
Periodic Table of Elements
... • Adding the protons and neutrons will give you the atomic mass. • For example Iron (Fe) has an atomic mass of 56 because there are 26 protons and 30 neutrons and added together that makes 56. ...
... • Adding the protons and neutrons will give you the atomic mass. • For example Iron (Fe) has an atomic mass of 56 because there are 26 protons and 30 neutrons and added together that makes 56. ...
Acrobat - chemmybear.com
... Just For Fun: 20. He studied matter in cathode ray tubes. 21. His philosophical idea included the term “atomos”. 22. He added to the atomic theory the idea that atoms had positive and negative parts. ...
... Just For Fun: 20. He studied matter in cathode ray tubes. 21. His philosophical idea included the term “atomos”. 22. He added to the atomic theory the idea that atoms had positive and negative parts. ...
J.J. Thomson and the Cathode Ray Tube 1897
... • By changing the electric field he found the moving particles were negative • This is still how all CRT TV’s work. • Don’t try this at home! MAGNET LINK ...
... • By changing the electric field he found the moving particles were negative • This is still how all CRT TV’s work. • Don’t try this at home! MAGNET LINK ...
Atomic Theory, cont*d
... Rutherford originally called this a proton, because it was positively charged. Later, it was renamed the nucleus. The nucleus of the atom has almost all the mass of the atom. Therefore, most of an atom is empty space. ...
... Rutherford originally called this a proton, because it was positively charged. Later, it was renamed the nucleus. The nucleus of the atom has almost all the mass of the atom. Therefore, most of an atom is empty space. ...
Rules for Naming Elements/Compounds
... – The atomic weight is basically a measurement of the total number of particles in an atom's nucleus. – All you really need to find is something called the mass number. – to find the mass number, all you need to do is round the atomic weight to the nearest whole number. – In the example, krypton's m ...
... – The atomic weight is basically a measurement of the total number of particles in an atom's nucleus. – All you really need to find is something called the mass number. – to find the mass number, all you need to do is round the atomic weight to the nearest whole number. – In the example, krypton's m ...