Chapter+4
... impractical to work with. It is more useful to compare the relative masses of atoms using a reference isotope as a standard The carbon-12 atom was assigned a mass of exactly 12 atomic mass units. Atomic mass unit (amu) – one twelfth of the mass of carbon-12 atom. ...
... impractical to work with. It is more useful to compare the relative masses of atoms using a reference isotope as a standard The carbon-12 atom was assigned a mass of exactly 12 atomic mass units. Atomic mass unit (amu) – one twelfth of the mass of carbon-12 atom. ...
Lecture 3 Chemistry
... Physical – H20 3 phases(solid, liquid, and gas) Chemical- composition Altered CH4 CO2 + H20 Structure: ...
... Physical – H20 3 phases(solid, liquid, and gas) Chemical- composition Altered CH4 CO2 + H20 Structure: ...
Atoms and their structure
... 3. TRUE - A compound has to have the same ratio of elements to be considered that particular compound – Ex H2O or H2O2 two different ratios mean, two different compounds 4. TRUE b/c of Law of _ _ _ _ _ _ _ _ _ _ _ _ _ _ ...
... 3. TRUE - A compound has to have the same ratio of elements to be considered that particular compound – Ex H2O or H2O2 two different ratios mean, two different compounds 4. TRUE b/c of Law of _ _ _ _ _ _ _ _ _ _ _ _ _ _ ...
Presentation
... • To make molecules, you must have elements. • Elements are made of atoms. While the atoms may have different weights and organization, they are all built in the same way. Information & picture from Chem4kids at http://www.chem4kids.com/files/atom_structure.html Created by G.Baker www.thesciencequee ...
... • To make molecules, you must have elements. • Elements are made of atoms. While the atoms may have different weights and organization, they are all built in the same way. Information & picture from Chem4kids at http://www.chem4kids.com/files/atom_structure.html Created by G.Baker www.thesciencequee ...
Introduction to Chemistry and Measurement
... means. • “116” elements have been identified • 82 elements occur naturally on Earth ...
... means. • “116” elements have been identified • 82 elements occur naturally on Earth ...
Chemistry Unit 1 Revision
... • They are unreactive and do not easily form molecules because their atoms have stable arrangements of electrons. • The noble gases have eight electrons in their outer energy level, except for helium, which has only two electrons. • The boiling points of the noble gases increase with increasing rela ...
... • They are unreactive and do not easily form molecules because their atoms have stable arrangements of electrons. • The noble gases have eight electrons in their outer energy level, except for helium, which has only two electrons. • The boiling points of the noble gases increase with increasing rela ...
Atoms - Pleasantville High School
... • Electrons can be bumped up to a higher shell if hit by an electron or a photon of light. ...
... • Electrons can be bumped up to a higher shell if hit by an electron or a photon of light. ...
Atom
... The nucleus is the centre of an atom, containing protons and neutrons. The energy must be given out when 'excited' electrons fall from a high energy level to a low one. ...
... The nucleus is the centre of an atom, containing protons and neutrons. The energy must be given out when 'excited' electrons fall from a high energy level to a low one. ...
Review
... 5. What is the average atomic mass of silicon if 92.21 % of its atoms have a mass of 27.977 amu, 4.07 % have a mass of 28.976 amu, and 3.09 % have a mass of 29.974 amu? ...
... 5. What is the average atomic mass of silicon if 92.21 % of its atoms have a mass of 27.977 amu, 4.07 % have a mass of 28.976 amu, and 3.09 % have a mass of 29.974 amu? ...
Hydrogen Models 1
... one neutron in its nucleus is called Deuterium. Deuterium is not radioactive. Water made from deuterium is called heavy water because the extra neutron makes it heavier. It is used in nuclear reactors. The third isotope of hydrogen is known as Tritium. It has one proton and two neutrons in its nucle ...
... one neutron in its nucleus is called Deuterium. Deuterium is not radioactive. Water made from deuterium is called heavy water because the extra neutron makes it heavier. It is used in nuclear reactors. The third isotope of hydrogen is known as Tritium. It has one proton and two neutrons in its nucle ...
theory1 (osergienko v1)
... Cathode rays have identical properties regardless of the element used to produce them. All elements must contain identically charged electrons. Atoms are neutral, so there must be positive particles in the atom to balance the negative charge of the electrons Electrons have so little mass that a ...
... Cathode rays have identical properties regardless of the element used to produce them. All elements must contain identically charged electrons. Atoms are neutral, so there must be positive particles in the atom to balance the negative charge of the electrons Electrons have so little mass that a ...
File
... deflections were found. It was transparent to the alpha particles.) There were three major findings: 1) Almost all of the alpha particles went through the gold foil as if it were not even there. Those alpha particles, of course, continued on a straight-line path until they hit the detector screen. 2 ...
... deflections were found. It was transparent to the alpha particles.) There were three major findings: 1) Almost all of the alpha particles went through the gold foil as if it were not even there. Those alpha particles, of course, continued on a straight-line path until they hit the detector screen. 2 ...
The Atom
... called atoms. 2. Atoms are indestructible. 3. Atoms are solid but invisible. 4. Atoms are homogenous. 5. Atoms differ in size, shape, mass, position, and arrangement. He believed that the movements of atoms caused the changes in matter he observed However, he had no way of proving the existence of ...
... called atoms. 2. Atoms are indestructible. 3. Atoms are solid but invisible. 4. Atoms are homogenous. 5. Atoms differ in size, shape, mass, position, and arrangement. He believed that the movements of atoms caused the changes in matter he observed However, he had no way of proving the existence of ...
CHEMICAL REACTIONS Chapter 4
... Chemical reactions occur when bonds between the outermost parts of atoms (valence electrons) are broken then reformed. Chemical reactions involve changes in matter, the making of new materials with new properties, and energy changes. Symbols represent elements (C, O2), Formulas describe compou ...
... Chemical reactions occur when bonds between the outermost parts of atoms (valence electrons) are broken then reformed. Chemical reactions involve changes in matter, the making of new materials with new properties, and energy changes. Symbols represent elements (C, O2), Formulas describe compou ...
Chapter 2 Notes
... C. States of Matter- on Earth matter occurs in 4 physical states 1. solids- molecules are in a fixed position relative to each other; atoms or molecules may vibrate, but do not switch positions; a solid resists changes in shape and volume 2. liquids- atoms or molecules remain close to one another bu ...
... C. States of Matter- on Earth matter occurs in 4 physical states 1. solids- molecules are in a fixed position relative to each other; atoms or molecules may vibrate, but do not switch positions; a solid resists changes in shape and volume 2. liquids- atoms or molecules remain close to one another bu ...
About 440 B.C. Empedocles stated that all matter was composed of
... 2. All atoms of a given element are chemically identical to each other; Atoms of one element are different from the atoms of all other elements Page 1 Atomic Theory ...
... 2. All atoms of a given element are chemically identical to each other; Atoms of one element are different from the atoms of all other elements Page 1 Atomic Theory ...
Export To Word
... also use models created by their peers to analyze the number of subatomic particles and determine isotopes' names. All worksheets and data collection sheets are included. In this Model Eliciting Activity (MEA), students will use their knowledge of the organization of the periodic table and the basic ...
... also use models created by their peers to analyze the number of subatomic particles and determine isotopes' names. All worksheets and data collection sheets are included. In this Model Eliciting Activity (MEA), students will use their knowledge of the organization of the periodic table and the basic ...
Atoms, Molecules and Ions
... matter are atoms, and only whole numbers of atoms can combine to form compounds. He first described color blindness, and he kept a meteorological journal with over 200,000 observations during his lifetime. ...
... matter are atoms, and only whole numbers of atoms can combine to form compounds. He first described color blindness, and he kept a meteorological journal with over 200,000 observations during his lifetime. ...
Converting with Avogadro`s Number File
... Bell Ringer • Convert 6.3 grams of Ag to moles. Ag atomic mass is 107.8682 • Convert 7 moles of Kr to grams. Kr atomic mass is 83.798 • How many cm are in one meter? • How many km are in 1200 meters? • Draw what Niels Bohr purposed the atom to look like and what was this model called? ...
... Bell Ringer • Convert 6.3 grams of Ag to moles. Ag atomic mass is 107.8682 • Convert 7 moles of Kr to grams. Kr atomic mass is 83.798 • How many cm are in one meter? • How many km are in 1200 meters? • Draw what Niels Bohr purposed the atom to look like and what was this model called? ...
Protons, Neutrons, Electrons
... We know that atoms are made of protons, electrons, and neutrons. This sheet will discuss how we show the composition of atoms: How many p, e, and n a particular atom has. We will also relate the makeup of each element’s atoms to the periodic table. Key terms to know, covered on this sheet: Atomic nu ...
... We know that atoms are made of protons, electrons, and neutrons. This sheet will discuss how we show the composition of atoms: How many p, e, and n a particular atom has. We will also relate the makeup of each element’s atoms to the periodic table. Key terms to know, covered on this sheet: Atomic nu ...
The Atomic Theory
... Law of Multiple Proportions: If two elements combine to form more than one compound the different weights of one which combine with the same weight of the other are in the ration of small whole numbers. Law of Reciprocal Proportions: The weights of two (or more) substances which react separately wit ...
... Law of Multiple Proportions: If two elements combine to form more than one compound the different weights of one which combine with the same weight of the other are in the ration of small whole numbers. Law of Reciprocal Proportions: The weights of two (or more) substances which react separately wit ...
Groups of the Periodic Table
... The atoms of each element are represented by a chemical symbol. This usually consists of one or two different letters, but sometimes three letters are used for newly discovered elements. For example, O represents an oxygen atom, and Na represents a sodium atom. The first letter in a chemical symbol ...
... The atoms of each element are represented by a chemical symbol. This usually consists of one or two different letters, but sometimes three letters are used for newly discovered elements. For example, O represents an oxygen atom, and Na represents a sodium atom. The first letter in a chemical symbol ...
File
... Experiments lead to his discoveries: Elements are made up of identical atoms which cannot be created or destroyed. They can combine to form compounds in whole number ratios. Chemical reactions involve the breaking or creating of bonds but never changing elements into new elements. ...
... Experiments lead to his discoveries: Elements are made up of identical atoms which cannot be created or destroyed. They can combine to form compounds in whole number ratios. Chemical reactions involve the breaking or creating of bonds but never changing elements into new elements. ...
Chemical element
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A chemical element (or element) is a chemical substance consisting of atoms having the same number of protons in their atomic nuclei (i.e. the same atomic number, Z). There are 118 elements that have been identified, of which the first 94 occur naturally on Earth with the remaining 24 being synthetic elements. There are 80 elements that have at least one stable isotope and 38 that have exclusively radioactive isotopes, which decay over time into other elements. Iron is the most abundant element (by mass) making up the Earth, while oxygen is the most common element in the crust of the earth.Chemical elements constitute approximately 15% of the matter in the universe: the remainder is dark matter, the composition of it is unknown, but it is not composed of chemical elements.The two lightest elements, hydrogen and helium were mostly formed in the Big Bang and are the most common elements in the universe. The next three elements (lithium, beryllium and boron) were formed mostly by cosmic ray spallation, and are thus more rare than those that follow. Formation of elements with from six to twenty six protons occurred and continues to occur in main sequence stars via stellar nucleosynthesis. The high abundance of oxygen, silicon, and iron on Earth reflects their common production in such stars. Elements with greater than twenty six protons are formed by supernova nucleosynthesis in supernovae, which, when they explode, blast these elements far into space as planetary nebulae, where they may become incorporated into planets when they are formed.When different elements are chemically combined, with the atoms held together by chemical bonds, they form chemical compounds. Only a minority of elements are found uncombined as relatively pure minerals. Among the more common of such ""native elements"" are copper, silver, gold, carbon (as coal, graphite, or diamonds), and sulfur. All but a few of the most inert elements, such as noble gases and noble metals, are usually found on Earth in chemically combined form, as chemical compounds. While about 32 of the chemical elements occur on Earth in native uncombined forms, most of these occur as mixtures. For example, atmospheric air is primarily a mixture of nitrogen, oxygen, and argon, and native solid elements occur in alloys, such as that of iron and nickel.The history of the discovery and use of the elements began with primitive human societies that found native elements like carbon, sulfur, copper and gold. Later civilizations extracted elemental copper, tin, lead and iron from their ores by smelting, using charcoal. Alchemists and chemists subsequently identified many more, with almost all of the naturally-occurring elements becoming known by 1900. The properties of the chemical elements are summarized on the periodic table, which organizes the elements by increasing atomic number into rows (""periods"") in which the columns (""groups"") share recurring (""periodic"") physical and chemical properties. Save for unstable radioactive elements with short half-lives, all of the elements are available industrially, most of them in high degrees of purity.