1 TEST DATE:
... The nuclei of all atoms of a given element always have the same number of_________________ They will also have the same number of_____________________________ around the nucleus. Some atoms may have more or fewer____________________________ than will other atoms of the same element. Atoms of the sam ...
... The nuclei of all atoms of a given element always have the same number of_________________ They will also have the same number of_____________________________ around the nucleus. Some atoms may have more or fewer____________________________ than will other atoms of the same element. Atoms of the sam ...
The Structure of the Atom
... the 13. ________________. The nuclei of all atoms of a given element always have the same number of 14. ________________. They will also have the same number of 15. ________________ around the nucleus. Some atoms may have more or fewer 16. ________________ than will other atoms of the same element. ...
... the 13. ________________. The nuclei of all atoms of a given element always have the same number of 14. ________________. They will also have the same number of 15. ________________ around the nucleus. Some atoms may have more or fewer 16. ________________ than will other atoms of the same element. ...
Chapter 4 Atomic Structure
... 3) Atoms of different elements combine in simple whole-number ratios to form chemical compounds 4) In chemical reactions, atoms are combined, separated, or rearranged – but never changed into atoms of another element. ...
... 3) Atoms of different elements combine in simple whole-number ratios to form chemical compounds 4) In chemical reactions, atoms are combined, separated, or rearranged – but never changed into atoms of another element. ...
What`s Inside an Element
... When selecting elements for the models, consider the time you have available and the students you teach. Some of the elements have high atomic mass and will take time to add to their models, because of the high number of protons and electrons. Students will have an easier time if you make a sample m ...
... When selecting elements for the models, consider the time you have available and the students you teach. Some of the elements have high atomic mass and will take time to add to their models, because of the high number of protons and electrons. Students will have an easier time if you make a sample m ...
Mystery Isotopes
... Research uses of isotopes. (Suggested Answers: used to date fossils and rocks, used in medical research and treatment.) Research uses and/or the half-lives of specific isotopes. Determine the stability/instability of various isotopes. Which isotopes are more likely to go through radioactive decay?(S ...
... Research uses of isotopes. (Suggested Answers: used to date fossils and rocks, used in medical research and treatment.) Research uses and/or the half-lives of specific isotopes. Determine the stability/instability of various isotopes. Which isotopes are more likely to go through radioactive decay?(S ...
AtomMoleculeNaming_G1
... differences in particle size. Filtration usually involves separating a precipitate from solution. Crystallization: Separation is based upon differences in solubility of the components in a mixture. Distillation: Separation is based upon differences in volatility. Extraction: Separation is based upon ...
... differences in particle size. Filtration usually involves separating a precipitate from solution. Crystallization: Separation is based upon differences in solubility of the components in a mixture. Distillation: Separation is based upon differences in volatility. Extraction: Separation is based upon ...
Basic Background Review: Acid-Base , Redox, and Stable Isotopes
... reactants (negative ΔH) contributes to spontaneous reaction) •ΔS measure of relative degree of disorder in product and reactant—greater disorder in product than reactant (positive ΔS) contributes to spontaneous reaction ...
... reactants (negative ΔH) contributes to spontaneous reaction) •ΔS measure of relative degree of disorder in product and reactant—greater disorder in product than reactant (positive ΔS) contributes to spontaneous reaction ...
chemistry notes: atomic structure
... 1) All elements are composed of submicroscopic, indivisible particles called atoms. (He didn’t know about subatomic particles and how to split an atom.) 2) Atoms of the same element are identical. (Not really true, as we’ll see later.) Atoms of different elements are different. 3) Atoms of elements ...
... 1) All elements are composed of submicroscopic, indivisible particles called atoms. (He didn’t know about subatomic particles and how to split an atom.) 2) Atoms of the same element are identical. (Not really true, as we’ll see later.) Atoms of different elements are different. 3) Atoms of elements ...
Introduction to Atoms
... • Use the atomic number given to find the element. • Write the element symbol on the blanks (1st letter of the symbol is capitalized, 2nd (if present) is lower case. • Then write the full name of each element. • Periodic tables can be found in your agenda book or in the textbook inside covers. ...
... • Use the atomic number given to find the element. • Write the element symbol on the blanks (1st letter of the symbol is capitalized, 2nd (if present) is lower case. • Then write the full name of each element. • Periodic tables can be found in your agenda book or in the textbook inside covers. ...
I - Chemistry-at-PA
... C. One of the two sub-atomic particles that has a mass of 1 amu. It has a positive electrical charge. D. The third sub-atomic particle. Its mass is nearly 2000 time smaller than the other two. It carries a negative electrical charge. E. an individual atom of an element with a different number of neu ...
... C. One of the two sub-atomic particles that has a mass of 1 amu. It has a positive electrical charge. D. The third sub-atomic particle. Its mass is nearly 2000 time smaller than the other two. It carries a negative electrical charge. E. an individual atom of an element with a different number of neu ...
Chapter 4 Atomic Structure
... • Dalton’s atomic theory states that all atoms of a given element are identical. This is mostly true • Atoms of the same element can differ in the number of neutrons • most elements have two or more isotopes • Isotopes are atoms of the same element with different numbers of neutrons (and therefore d ...
... • Dalton’s atomic theory states that all atoms of a given element are identical. This is mostly true • Atoms of the same element can differ in the number of neutrons • most elements have two or more isotopes • Isotopes are atoms of the same element with different numbers of neutrons (and therefore d ...
ATOMS AND ELEMENTS Evolution of Atomic Theory
... ¨ Therefore, the number of electrons in an atom is equal to the number of protons in an atom (Z) for any neutral atom. ¨ Atoms which contain more or less electrons than protons therefore must have a charge. These are called ions. ...
... ¨ Therefore, the number of electrons in an atom is equal to the number of protons in an atom (Z) for any neutral atom. ¨ Atoms which contain more or less electrons than protons therefore must have a charge. These are called ions. ...
Honors Chemistry Ms. K Pages 66
... what would be produced? (Write the nuclear equation for this process.) ...
... what would be produced? (Write the nuclear equation for this process.) ...
Calculating the number of Protons, Neutrons, and Electrons.
... Atomic Number = Protons and Electron Calculate Neutrons = Rounded Atomic Mass – Atomic Number EXAMPLE: 15.999 rounds to 16 so ...
... Atomic Number = Protons and Electron Calculate Neutrons = Rounded Atomic Mass – Atomic Number EXAMPLE: 15.999 rounds to 16 so ...
Test Review Chapter 1
... 1. The law of conservation of mass follows from the concept that a. atoms are indivisible. b. atoms of different elements have different properties. c. matter is composed of atoms. d. atoms can be destroyed in chemical reactions. 2. According to the law of definite proportions, any two samples of KC ...
... 1. The law of conservation of mass follows from the concept that a. atoms are indivisible. b. atoms of different elements have different properties. c. matter is composed of atoms. d. atoms can be destroyed in chemical reactions. 2. According to the law of definite proportions, any two samples of KC ...
Atomic Mass
... neutrons is the mass number = 12 atomic mass units Mass Number (A) = # protons + # neutrons NOT on the periodic table…(Round the AVERAGE atomic mass on the table) A boron atom can have ...
... neutrons is the mass number = 12 atomic mass units Mass Number (A) = # protons + # neutrons NOT on the periodic table…(Round the AVERAGE atomic mass on the table) A boron atom can have ...
weighted average - Effingham County Schools
... definition of an element as a substance that cannot be further broken down by ordinary chemical means. •It was also clear that elements combine to form compounds that have different physical and chemical properties than those of the elements that form them. Na + Cl → NaCl ...
... definition of an element as a substance that cannot be further broken down by ordinary chemical means. •It was also clear that elements combine to form compounds that have different physical and chemical properties than those of the elements that form them. Na + Cl → NaCl ...
Chemistry: Matter and Change
... What happens when an element emits radioactive particles? A. It gains energy. B. It gains neutrons. ...
... What happens when an element emits radioactive particles? A. It gains energy. B. It gains neutrons. ...
Atoms and their structure
... 2. 1st part FALSE b/c of discovery of ions and isotopes for atoms of the same element (Ex: Carbon12 vs. Carbon-14 and H+ vs. H); 2nd part TRUE 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 differe ...
... 2. 1st part FALSE b/c of discovery of ions and isotopes for atoms of the same element (Ex: Carbon12 vs. Carbon-14 and H+ vs. H); 2nd part TRUE 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 differe ...
isotopes and average atomic mass
... The atomic mass of an element is the sum of all the masses of the sub-atomic particles which comprise the atom. The mass in grams of these particles (protons, neutrons, electrons, et al) are exceptionally small. The mass of the proton is 1.67 X 10-23 grams. The neutron is slightly larger and the ele ...
... The atomic mass of an element is the sum of all the masses of the sub-atomic particles which comprise the atom. The mass in grams of these particles (protons, neutrons, electrons, et al) are exceptionally small. The mass of the proton is 1.67 X 10-23 grams. The neutron is slightly larger and the ele ...
Atoms and Elements
... Prediction of New Elements • Mendeleev noticed that there appeared to be some elements missing from the periodic table. • He was able to accurately predict the properties of the unknown element ekasilicon in 1869. • The element was actually discovered in 1886 (Germanium). ...
... Prediction of New Elements • Mendeleev noticed that there appeared to be some elements missing from the periodic table. • He was able to accurately predict the properties of the unknown element ekasilicon in 1869. • The element was actually discovered in 1886 (Germanium). ...
1. Structure and Properties of the Atom
... Atoms of different elements can combine with one another in simple (whole number) ratios to form compounds. ...
... Atoms of different elements can combine with one another in simple (whole number) ratios to form compounds. ...
Rules for Calculating Protons, Neutrons, Electrons, Atomic Number
... The ATOMIC NUMBER, PROTONS, and ELECTRONS are always the same. EX) If the atomic number of an atom is 15, then the number of protons is 15 and the number of electrons is 15. To calculate the number of NEUTRONS in an atom, you take the ATOMIC NUMBER and SUBTRACT is from the ROUNDED ATOMIC MASS to the ...
... The ATOMIC NUMBER, PROTONS, and ELECTRONS are always the same. EX) If the atomic number of an atom is 15, then the number of protons is 15 and the number of electrons is 15. To calculate the number of NEUTRONS in an atom, you take the ATOMIC NUMBER and SUBTRACT is from the ROUNDED ATOMIC MASS to the ...
ExamView - Chapter 4 Test.tst
... ____ 29. Which of the following equals one atomic mass unit? a. the mass of one electron b. the mass of one helium-4 atom c. the mass of one carbon-12 atom d. one-twelfth the mass of one carbon-12 atom ____ 30. Why do chemists use relative masses of atoms compared to a reference isotope rather than ...
... ____ 29. Which of the following equals one atomic mass unit? a. the mass of one electron b. the mass of one helium-4 atom c. the mass of one carbon-12 atom d. one-twelfth the mass of one carbon-12 atom ____ 30. Why do chemists use relative masses of atoms compared to a reference isotope rather than ...
atomic mass number - Magoffin County Schools
... 1. Write the CHEMICAL SYMBOL and AMN Example C-14 ...
... 1. Write the CHEMICAL SYMBOL and AMN Example C-14 ...
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.