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| What is the smallest particle of an element that still retains the chemical properties of that element? | An ATOM is the least unit possessing the chemical particles of an elemental substance. |
| As early as 400 B.C. , certain Greek thinkers such as Democritus supported what theory of matter? | The particle theory of matter laid the basic foundations of many early Greek scientist and persons of influence regarding the world about us. |
| According to Democritus, what was nature's basic particle? | The atom, which in Greek meant "indivisible" |
| True or false? The Greek thinker Democritus was preceeded by Aristoltle and his generation of of thinkers/scientists. | False, Aristole was in the immediate generation of thinkers/scientist whom follwed the Greek thinker Democritus |
| Either Democritus or Aristotle was an early thinker whom did NOT believe in the atom concept, which? | Aristotle was part of the generation that succeeded Democritus, and Aristotle's ideas had a lasting impact on Western Civilization.Aristotle displayed a disbelief in atoms. |
| I am an early thinker in science whom believed that all matter is continuous, I do NOT believe in the atom. I was so convincing that for nearly 2000 years my opinion was accepted, who am I? | Aristotle |
| Experimental data and investigation such as experimental evidence was NOT supportive of our thoughts of matter, for this reason our ideas remaind speculation , although accepted by many, until the eighteenth century.Who are we? | Democritus and Aristotle's ideas showed unfavorable results up against experimental testing and therefore always remained suspect although generally accepted because , at that time, no other ideas rose up far enough to replace the ideas and concepts of either. |
| In what century did scientist finally begin to gather evidence that favored the atomic theory of matter? | Finally in the Eighteenth century, scientists and experimental data/investigations began displaying support for the belief that all matter was composed of minute units called atoms. |
| In the late 1700s virtually all scientist already had accepted the modern definition of an element ( a substance that can NOT be further broken down by ORDINARY chemical means) and there was certainly enough documentation evidence to support universally that elements combine to form compounds that do have different physical and chemical properties from those of the elements that form them. However, there was GREAT CONTROVERSY as to what when speaking about elements forming a new compound? | The not so certain concept centered around to whether or not elements ALWAYS combined in the same ratio when forming a particular compound. |
| What is the transformation of a substance or substances into one or more new substances? | a chemical reaction |
| What states that mass is neither created nor destroyed during an ordinary chemical reactions or ordinary physical changes. | Law of Conservation of Mass |
| True or false? Regardless of where or how a pure chemical compound is prepared , it is nonetheless still composed of a fixed proportion of elements? | TRUE, iregardless of manner composed, a pure substance will infinitely possess a definitive ratio of the elements that make up the pure substance. |
| This is the Law of Definitive Proprtions. | The fact that a chemical compound contains the same elements in exactly the same proportions by mass irregardless of the size of the sample or source of the compound. |
| Sometimes two elements can combine to form _______?_______. | More than one compound |
| This is the Law of Multiple Proportions. | If two or more different compounds are composed of the same two elements, then the ratio of the masses of the second element combined with a certain mass of the first element is always a ratio of small whole numbers. |
| I was an English schoolteacher whom, in 1808, proposed an explanation for the law of conservation of mass, the law of definitive proportions, and the law of multiple proportions.Also, I reasoned that elements were composed of atoms and that only whole numbers of atoms can combine to form compound. | John Dalton |
| Stated that (1) all matter is composed of extremely small particles called atoms , (2) atoms of a given element are identical in size, mass, and other properties ( ...that atoms of different elements differ in size, mass and other properties) , (3) atoms can not be subdivided, created, nor destroyed , (4) atoms of different elements combine in simple whole-number ratios to form chemical compounds , and (5) in chemical reactions, atoms are combined , separated, or rearranged. | Dalton's Atomic Theory |
| According to Dalton's Atomic Theory, the _______________?__________ is explained by the fact that chemical reactions involve merely the combination, separation, or ______?______ of atoms and that during these processes atoms are not subdivided, created , nor ____?____. | Law of conservation of mass, rearrangement , destroyed |
| This is the law that resulted from the fact that a given chemical compound is always composed of the same combination of atoms. | Law of Definitive Proportions |
| True or False? John Dalton's Atomic Theory is today known to be correct. | False....not all aspects of this theory have been proven correct.For example, today we know that atoms are infact divisible into even smaller particles although the Law of Conservation of Mass still holds true for chemical reactions, and we also know, today, that a given element can have atoms of differing masses. |
| Although shown to be partially incorrect, scientist today still have not completely discarded the Atomic Theory by John Dalton.Instead, scientist have since done what? | Because of certain flaws in the original writing of this theory, scientist have MODIFIED it in such a manner that it can explain the new observations. |
| Despite some of the modifications to Dalton's Atomic Theory made by scientist over the years since Dalton proposed his explaination of several laws, these important concepts remain unchanged and credited to Dalton. | All matter is composed of atoms AND atoms of any one element differ in properties from atoms of another element |
| All atoms of a given element do not neccessarily have the same mass, TRUE or False? | Scientist today realize that atoms of a particular element may or maynot possess similar number of neutrons, hence meaning differing atoms of a particular element may have varying atomic masses although all atoms of any given element will always possess only atoms with the same atomic number. |
| We are atoms of the same exact element, possessing exactly same number of protons and therefore electons as well, but we differ in the number of neutrons we possess. We are called what? | isotopes |
| The ability of scientists to divide atoms into protons,neutrons,and electrons and then to further divide protons and neutrons into quarks is an example of what? | why atoms are no longer believed to be indivisible as Dalton's Atomic Theory suggested, incorrectly. |
| We focus on understanding the physical properties of atoms and molecules. | Physical Chemist |
| In addition to xchemistry, physical chemist must study and excell in subject areas of what else too? | mathematics and physics are essential tools in being proficient scientists of this field |
| This now gives scientist what they have yearned for many years, the ability to "see" individual atoms.What allows scientists the ability to look at individual atoms, invented in 1981? | The Scanning Tunneling Microscope, or STM |
| We shared the 1986 Nobel Prize in physics for our discovery of the scanning tunneling microscope (STM), who are we? | Gerd Binning and Heinrich Rohrer |
| This is a developing subdiscipline in physical chemistry of which the STM is an incredibly important tool in the field . | Surface Chemistry...The scanning tunneling microscope is utilized to study surface reactions, such as those that take place in catalytic converters. |
