mc06sete_c03ct_018
... c. a dense region of positive charge existed somewhere in the atom. d. light was emitted by electrons returning to ground state. _____ 5. Which of the following is not one of the five principles of Dalton’s theory? a. Atoms of different elements combine in simple, whole-number ratios to form compoun ...
... c. a dense region of positive charge existed somewhere in the atom. d. light was emitted by electrons returning to ground state. _____ 5. Which of the following is not one of the five principles of Dalton’s theory? a. Atoms of different elements combine in simple, whole-number ratios to form compoun ...
Unit 3 Notes only
... These elements are called: RADIOACTIVE When these elements decay their nucleus changes into another element and they give off RADIATION. ...
... These elements are called: RADIOACTIVE When these elements decay their nucleus changes into another element and they give off RADIATION. ...
Atoms - Peoria Public Schools
... • Dalton’s atomic theory has five points: – All matter is composed of extremely small particles called atoms. – Atoms of an element are identical in size, mass and other properties; atoms of different elements differ in size, mass, and other properties. – Atoms cannot be subdivided, created, or dest ...
... • Dalton’s atomic theory has five points: – All matter is composed of extremely small particles called atoms. – Atoms of an element are identical in size, mass and other properties; atoms of different elements differ in size, mass, and other properties. – Atoms cannot be subdivided, created, or dest ...
Atomic Structure
... • The smaller of the 2 numbers is called The Proton Number or The Atomic Number, Z • This tell us how many protons are in the nucleus of an atom. • The bigger number tells us the total number of protons AND neutrons in the atom • This may be called The Nucleon Number or The ...
... • The smaller of the 2 numbers is called The Proton Number or The Atomic Number, Z • This tell us how many protons are in the nucleus of an atom. • The bigger number tells us the total number of protons AND neutrons in the atom • This may be called The Nucleon Number or The ...
SUBATOMIC PARTICLES The three main subatomic particles found
... All atoms of the same element must have the same number of protons, but they may vary in their number of neutrons. Atoms of the same element with ...
... All atoms of the same element must have the same number of protons, but they may vary in their number of neutrons. Atoms of the same element with ...
11129_evl_ch1_ste_eleve (3)
... is used extensively today in cellphone batteries and will also be used, in the near future, in batteries for hybrid or electric cars. In 2008, one battery out of every four sold in the world was manufactured in China. China therefore has a certain economic interest in Tibet. Mining the resource is r ...
... is used extensively today in cellphone batteries and will also be used, in the near future, in batteries for hybrid or electric cars. In 2008, one battery out of every four sold in the world was manufactured in China. China therefore has a certain economic interest in Tibet. Mining the resource is r ...
4-2: Structure of the Atom
... electrons in order to get a full valence shell. When an atom either gains one or more electrons or loses one or more electrons, the atom is no longer neutrally charged. When an atom or a group of atoms has either a negative or a positive charge it is called an _________. ...
... electrons in order to get a full valence shell. When an atom either gains one or more electrons or loses one or more electrons, the atom is no longer neutrally charged. When an atom or a group of atoms has either a negative or a positive charge it is called an _________. ...
File - Johnson
... • Each element is composed of extremely small particles called atoms • All atoms of a given element are identical, but they differ from those of any other element • Atoms are neither created nor destroyed in any chemical rxn • A given compound always has the same relative numbers and kinds of atoms ...
... • Each element is composed of extremely small particles called atoms • All atoms of a given element are identical, but they differ from those of any other element • Atoms are neither created nor destroyed in any chemical rxn • A given compound always has the same relative numbers and kinds of atoms ...
A Few Laws • Conservation of Matter-For any
... mean atomic masses based upon the natural isotopic abundances of the element. • The calculation of a mean atomic mass is straightforward and illustrated in your text several times. This calculation will not be asked on quizzes or exams, but students should be able to answer questions like: Element X ...
... mean atomic masses based upon the natural isotopic abundances of the element. • The calculation of a mean atomic mass is straightforward and illustrated in your text several times. This calculation will not be asked on quizzes or exams, but students should be able to answer questions like: Element X ...
Chapter 18 Comparing Atoms Lab
... many marbles, and of as many colors as they need but must take at least as many total marbles as they put in. For example, a player can trade 2 yellows for 1 yellow, 1 blue, and 1 red. 11. Which particles are found in an atom’s nucleus? Which particles are found outside the nucleus? 12. What four el ...
... many marbles, and of as many colors as they need but must take at least as many total marbles as they put in. For example, a player can trade 2 yellows for 1 yellow, 1 blue, and 1 red. 11. Which particles are found in an atom’s nucleus? Which particles are found outside the nucleus? 12. What four el ...
Chapter 4: Atoms and Elements
... Nonmetals of groups VA, VIA, and VIIA gain one or more electrons to get the same number of valence electrons as the nearest noble gas. Note: ...
... Nonmetals of groups VA, VIA, and VIIA gain one or more electrons to get the same number of valence electrons as the nearest noble gas. Note: ...
Pre-AP Review Unit 2
... Protons, electrons, and neutrons are evenly distributed throughout the atom. The nucleus is made of protons, electrons, and neutrons. Electrons are located around the nucleus and occupy most of the volume. The nucleus is made of electrons and protons. ...
... Protons, electrons, and neutrons are evenly distributed throughout the atom. The nucleus is made of protons, electrons, and neutrons. Electrons are located around the nucleus and occupy most of the volume. The nucleus is made of electrons and protons. ...
Atomic Mass - Coach ONeal
... are called isotopes. • Models of two isotopes of boron are shown. Because the numbers of neutrons in the isotopes are different, the mass numbers are also different. • You use the name of the element followed by the mass number of the isotope to identify each isotope: boron-10 and boron-11. ...
... are called isotopes. • Models of two isotopes of boron are shown. Because the numbers of neutrons in the isotopes are different, the mass numbers are also different. • You use the name of the element followed by the mass number of the isotope to identify each isotope: boron-10 and boron-11. ...
Atomic Structure Notes file
... The atoms of an element can differ in mass from each other because they have differing numbers of neutrons. Those with more neutrons will weigh more and be more massive. The atomic mass (often referred to as atomic weight) of an element is calculated by adding together the number of protons and the ...
... The atoms of an element can differ in mass from each other because they have differing numbers of neutrons. Those with more neutrons will weigh more and be more massive. The atomic mass (often referred to as atomic weight) of an element is calculated by adding together the number of protons and the ...
Chapter 4
... Halogen atoms usually gain or share ____ one electron when it reacts with other elements. • All halogens are __________ Very reactive and can be dangerous to humans. • Many compounds that contain halogens can be useful to humans – salt, flourine in water, calcium ...
... Halogen atoms usually gain or share ____ one electron when it reacts with other elements. • All halogens are __________ Very reactive and can be dangerous to humans. • Many compounds that contain halogens can be useful to humans – salt, flourine in water, calcium ...
atom - BobcatChemistry
... • Gamma rays are high-energy radiation with no mass and are neutral and cannot, by themselves, result in the formation of a new atom. • Gamma rays account for most of the energy lost during radioactive decay. ...
... • Gamma rays are high-energy radiation with no mass and are neutral and cannot, by themselves, result in the formation of a new atom. • Gamma rays account for most of the energy lost during radioactive decay. ...
Chapter 3—Time and Geology
... b. Radiometric dating works differently on Earth than it does on other planets. c. The Earth formed from a collision of a meteorite with the Moon. d. The Earth is geologically active and older rocks may have been altered and converted to other rocks by geologic processes such as erosion, metamorphis ...
... b. Radiometric dating works differently on Earth than it does on other planets. c. The Earth formed from a collision of a meteorite with the Moon. d. The Earth is geologically active and older rocks may have been altered and converted to other rocks by geologic processes such as erosion, metamorphis ...
Atomic Structure - What you should already know
... Atomic Number (Z) – this is unique to each atom. The atomic number is equal to the number of protons. Mass Number (A) – this is the total mass of each atom. Remember, each P and N has a mass of ...
... Atomic Number (Z) – this is unique to each atom. The atomic number is equal to the number of protons. Mass Number (A) – this is the total mass of each atom. Remember, each P and N has a mass of ...
1 An atom is the smallest particle of any element that still retains the
... a) Alpha Radiation. (α). It consists of a stream of positively charged particles, called alpha particles, which have an atomic mass of 4 and a charge of +2 ( a helium nucleus). b) Beta Radiation. β. It is a stream of electrons ( from nucleus), called beta particles. When a beta particle is ejected, ...
... a) Alpha Radiation. (α). It consists of a stream of positively charged particles, called alpha particles, which have an atomic mass of 4 and a charge of +2 ( a helium nucleus). b) Beta Radiation. β. It is a stream of electrons ( from nucleus), called beta particles. When a beta particle is ejected, ...
pdf.format - San Diego Mesa College
... Elements are made from atoms having the same atomic number, protons Are all atoms of one particular atom the same or are they mixtures? 1) All atom nuclei for an element have the same number of protons. 2) Every atom in an element has the same number of protons & electrons. 3) However, elements are ...
... Elements are made from atoms having the same atomic number, protons Are all atoms of one particular atom the same or are they mixtures? 1) All atom nuclei for an element have the same number of protons. 2) Every atom in an element has the same number of protons & electrons. 3) However, elements are ...
Promethium
Promethium, originally prometheum, is a chemical element with symbol Pm and atomic number 61. All of its isotopes are radioactive; it is one of only two such elements that are followed in the periodic table by elements with stable forms, a distinction shared with technetium. Chemically, promethium is a lanthanide, which forms salts when combined with other elements. Promethium shows only one stable oxidation state of +3; however, a few +2 compounds may exist.In 1902, Bohuslav Brauner suggested there was an element with properties intermediate between those of the known elements neodymium (60) and samarium (62); this was confirmed in 1914 by Henry Moseley who, having measured the atomic numbers of all the elements then known, found there was an element with atomic number 61. In 1926, an Italian and an American group claimed to have isolated a sample of element 61; both ""discoveries"" were soon proven to be false. In 1938, during a nuclear experiment conducted at Ohio State University, a few radioactive nuclides were produced that certainly were not radioisotopes of neodymium or samarium, but there was a lack of chemical proof that element 61 was produced, and the discovery was not generally recognized. Promethium was first produced and characterized at Oak Ridge National Laboratory in 1945 by the separation and analysis of the fission products of uranium fuel irradiated in a graphite reactor. The discoverers proposed the name ""prometheum"" (the spelling was subsequently changed), derived from Prometheus, the Titan in Greek mythology who stole fire from Mount Olympus and brought it down to humans, to symbolize ""both the daring and the possible misuse of mankind's intellect"". However, a sample of the metal was made only in 1963.There are two possible sources for natural promethium: rare decays of natural europium-151 (producing promethium-147), and uranium (various isotopes). Practical applications exist only for chemical compounds of promethium-147, which are used in luminous paint, atomic batteries, and thickness measurement devices, even though promethium-145 is the most stable promethium isotope. Because natural promethium is exceedingly scarce, it is typically synthesized by bombarding uranium-235 (enriched uranium) with thermal neutrons to produce promethium-147.