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Nature of Atoms Atomic Structure
Nature of Atoms Atomic Structure

... between the partially negative O atoms and the partially positive H atoms of two water ...
1st Six Weeks Review
1st Six Weeks Review

... 20. What is average atomic mass? How do you calculate it? Weighted average of the naturally occuring isotopes of that element. ...
Chapter 8
Chapter 8

The Material World: An Introduction to Chemistry 1. Modern Model of
The Material World: An Introduction to Chemistry 1. Modern Model of

... The chemical properties of isotopes are almost identical. The extra weight sometimes slows down the rate at which things react, but it does not affect whether they react. Example: ...
Key Concept 1: An atom is the smallest unit of an element that
Key Concept 1: An atom is the smallest unit of an element that

... Key Concept 7: Electrons are located outside of the nucleus and arranged by energy levels in the electron cloud. There are a certain number of electrons that each energy level can hold. ...
Slide 1
Slide 1

... John Dalton (1766–1844), • Atoms of different elements have different properties. • Atoms of different elements can combine in specific ways to form new substances. • Atoms cannot be created, destroyed, or subdivided in a chemical change. ...
Unit 2: Atomic Theory Vocab
Unit 2: Atomic Theory Vocab

... Atomic Mass – the average mass of all naturally occurring isotopes for an element Atomic Mass unit (a.m.u.) – 1/12th the mass of a Carbon-12 atom; the mass of one proton or one neutron Atomic number – the number of protons in an atom of a given element Ex: The atomic # of carbon is 6, which means th ...
key concepts of matter
key concepts of matter

... Key Concept 1: An element can be identified by its atomic number, or the number of protons located in its nucleus. Key Concept 2: Electrons are located outside of the nucleus and arranged by energy levels in the electron cloud. There are a certain number of electrons that each energy level can hold. ...
02Ch02chemistry2005
02Ch02chemistry2005

... Elements & their valence shells  Moving from left to right, each element has a sequential addition of electrons (and protons) ...
Isotopes are atoms of the same element that have different masses
Isotopes are atoms of the same element that have different masses

... other has 10 neutrons. Therefore, the masses are 16 amu and 18 amu respectively. ...
01 Intro Chemistry
01 Intro Chemistry

... Elements & their valence shells  Moving from left to right, each element has a sequential addition of electrons (and protons) ...
Atomic Theory Powerpoint
Atomic Theory Powerpoint

... masses of atoms are so small, it is more convenient to use relative atomic masses instead of real masses  to set up a scale, we have to pick one atom to be the standard  since 1961, the carbon-12 nuclide is the standard and is assigned a mass of ...
Chapter 2 Chemistry
Chapter 2 Chemistry

...  All atoms of an element have same chemical properties all behave the same  properties don’t change ...
Chapter 2 2012
Chapter 2 2012

... that explains radioactivity, fission and atomic bombs ...
Atomic Structure
Atomic Structure

... – Different energy levels – Represented by areas of probability • Areas become larger with energy • Electrons can be anywhere in the probability area ...
Chapter 3
Chapter 3

... by mass for example: NaCl is always 66.66% chlorine and 39.34% sodium • Law of Multiple Proportions: when two elements can form two compounds, the masses that combine are in simple whole number ratios, CO and CO2 ...
Chapter 3
Chapter 3

... by mass for example: NaCl is always 60.66% chlorine and 39.34% sodium • Law of Multiple Proportions: when two elements can form two compounds, the masses that combine are in simple whole number ratios, CO and CO2 ...
File
File

... arrangement is significant. The elements in each vertical column or group have similar properties. The elements in the first period or row all have one shell. The elements in period 2 all have 2 shells and so on. There are a number of major groups with similar properties. They are as follows: Hydrog ...
Chemistry Notes (pg. # 1)
Chemistry Notes (pg. # 1)

... Question: What makes one element different from another? ...
Atomic Structure
Atomic Structure

... If the number of protons changes then the identity of the element changes with it! Atomic Number (Z) – the number of protons in the nucleus of each atom of that element Z = # of protons ...
Atomic Structure
Atomic Structure

... have different numbers of neutrons, and thus different mass numbers • Isotopes are referred to by their name and mass number when needed (example: hydrogen-1 and hydrogen-2) • Example: heavy water is made up of two hydrogen-2 atoms bound to oxygen ...
TEST on Atomic Structure
TEST on Atomic Structure

... 23. _b__ the identity of an element is determined by the number of ___________ in the nucleus 24. _p__ one-half the distance between the nuclei of two atoms when the atoms are joined 25. _d__ a negatively charged subatomic particle 26. _b__ a positively charged subatomic particle 27. _g__ the weight ...
Atoms
Atoms

... __________________ F, 19 - 9 = 10 neutrons Mg, 24 - 12 = 12 neutrons Magnesium __________________ ...
Chapter 2
Chapter 2

Chapter 2
Chapter 2

... hypothetical construct, but not real entities because no direct evidence for them existed with the technology of that time. By the late 1800s, physicists knew that passing an electrical current between two metal plates in an evacuated tube containing a fluorescent screen produced a green trace. It w ...
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Extended periodic table

An extended periodic table theorizes about elements beyond element 118 (beyond period 7, or row 7). Currently seven periods in the periodic table of chemical elements are known and proven, culminating with atomic number 118. If further elements with higher atomic numbers than this are discovered, they will be placed in additional periods, laid out (as with the existing periods) to illustrate periodically recurring trends in the properties of the elements concerned. Any additional periods are expected to contain a larger number of elements than the seventh period, as they are calculated to have an additional so-called g-block, containing at least 18 elements with partially filled g-orbitals in each period. An eight-period table containing this block was suggested by Glenn T. Seaborg in 1969. IUPAC defines an element to exist if its lifetime is longer than 10−14 seconds, which is the time it takes for the nucleus to form an electronic cloud.No elements in this region have been synthesized or discovered in nature. The first element of the g-block may have atomic number 121, and thus would have the systematic name unbiunium. Elements in this region are likely to be highly unstable with respect to radioactive decay, and have extremely short half lives, although element 126 is hypothesized to be within an island of stability that is resistant to fission but not to alpha decay. It is not clear how many elements beyond the expected island of stability are physically possible, if period 8 is complete, or if there is a period 9.According to the orbital approximation in quantum mechanical descriptions of atomic structure, the g-block would correspond to elements with partially filled g-orbitals, but spin-orbit coupling effects reduce the validity of the orbital approximation substantially for elements of high atomic number. While Seaborg's version of the extended period had the heavier elements following the pattern set by lighter elements, as it did not take into account relativistic effects, models that take relativistic effects into account do not. Pekka Pyykkö and B. Fricke used computer modeling to calculate the positions of elements up to Z = 184 (comprising periods 8, 9, and the beginning of 10), and found that several were displaced from the Madelung rule.
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