All matter is made up of atoms. An atom is like a tiny solar system. In the center of the atom is the nucleus which is a cluster of protons and neutrons. The protons have a positive electric charge while the neutrons are electrically neutral. The nucleus makes up almost all of an atom's mass or weight. Whirling at fantastic speeds around the nucleus are smaller and lighter particles called electrons which have a negative electric charge. . The protons have a positive electric charge while the neutrons are electrically neutral. The nucleus makes up almost all of an atom's mass or weight. Whirling at fantastic speeds around the nucleus are smaller and lighter particles called electrons which have a negative electric charge. An atom has the same number of electrons with positive charge and negative charge. An extremely powerful force, called the nuclear force, holds the protons together in the nucleus as they naturally repelled one another electrically. The atoms of each chemical element have a different nucleus. An atom of hydrogen has one proton and no neutrons. An atom of nitrogen has 7 protons and 7 neutrons. Heavy elements have a large number of protons and neutrons. For example, the most common isotope of uranium, uranium-238 has 92 protons and 146 neutrons in its nucleus. Protons are positively charged and so would be deflected on a curving path towards the negative plate. Electrons are negatively charged and so would be deflected on a curving path towards the positive plate. Neutrons don't have a charge, and so would continue on in a straight line. Isotopes are atoms which have the same atomic number but different mass numbers. They have the same number of protons but different numbers of neutrons. The electrons are found at considerable distances from the nucleus in a series of levels called energy levels. Each energy level can only hold a certain number of electrons. Atomic theory, first put in a quantitative conceptual framework by John Dalton, and quantum theory, which emerged in the 1920s as a result of the work of Werner Heisenberg, Erwin Schrödinger, and Max Planck, are the cornerstones of our present-day view on atomic structure. Atomic theory holds that matter consists of vast numbers of small particles called atoms which combine together to form molecules existing in the three main states of matter as gases, liquids or solids. Thomson's experiments led him to propose a "plum-pudding" view of the atom in which a continuous distribution of positive mass extends over the size of the atom with negative "plums" of much smaller mass (i.e. electrons) inserted into it. This model was overthrown by a series of alpha particle scattering experiments carried out by Rutherford, Hans Geiger and Ernest Madden. They were able to observe back-scattering of alpha particles emitted by a piece of radium as they were being shot through a thin gold foil. The fact that alpha particles are positive and that some of them were scattered back could only be explained by proposing that the positive charge and mass in the gold atoms making up the foil could not be continuous and had to be concentrated in a very small region and that the negative region had to be large enough to let some alpha particles through. This led to a view of the atom in which the positive nucleus is central, very dense and significantly smaller than the size of the overall atom. Modern neutron scattering experiments have shown that the radius of a nucleus is proportional to the cubic root of its mass number and that atomic radii, including electron clouds, are about twenty thousand times bigger with a spherical shape or elongated like a football. The view that electrons can be thought of as being arranged in successive shells of increasing energy around the nucleus is called the Bohr model of the atom and one of the most significant contributions of quantum theory has been to show that these energy levels are quantized. This led to the orbital…
Chem 100 Research Project: Essay Outline
Lasers & Medicine
A. Definitions of Lasers and Medicine
1. Laser is a device that emits light through a process of optical amplification
based on the stimulated emission of electromagnetic radiation.
2. Medicine is the applied science or practice of the diagnosis, treatment, and
prevention of disease.
B. How they relate?
1. Cure diseases, surgeries, etc.
For centuries upon centuries, humans have developed ideas based on their experimental findings. Due to the fluidity of science, these ideas have been through many stages before the most plausible one is decided upon. Atomic theory began with Greek philosophers in Ancient times and carried over to modern science. The knowledge acquired by past scientists has had a great impact on discoveries made by those that followed. Furthermore, the models of the atom that Ernest Rutherford and J.J. Thomson…
Chemistry Midterm 2013:
1) Physical Change vs. Chemical Change:
Physical changes are limited to changes that result in a difference in display without changing the composition. Some common changes (but not limited to) are:
Change of State (Boiling Point and Melting Point are significant factors in determining this change.)
Physical properties include many other aspects of a substance. The following are (but not limited to) physical properties…
Required Knowledge (Preliminary Course)
Energy from Fossil Fuels
Originates from sun - solar to chemical by photosynthesis.
Red and violet wavelengths of sunlight absorbed by pigment chlorophyll, energy converted to chemical energy in glucose.
Glucose – carbohydrate: high-energy compound of C, H and O.
6CO2(g) + 6H2O(l) + energy C6H12O6(aq) + 6O2(g)
Petroleum consists of cruide oil and natural gas, formed of remains of single-celled marine organisms.
Quick burial, decay by bacteria…
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Anything occupying space and having mass is matter
Matter exists in three states
Kangaroos Hop Down Mountains During Cold Months
Killo Hecto Deca Meter Deci Centi Milli
10^3 “”^2 “”^1 10^-1 10^-2 10^-3….
Solid- ridged, particles cannot slide past each other
Liquid-has definite volume, but shape
Experimental Absorbance (cm-1)
Functional groups/ Bonding
Sp3 C-H Stretch
Sp3 C-H Stretch
Sp3 C-H Stretch
C=O carbonyl stretch
The objective of the experiment was to oxidize a secondary alcohol, isoborneol to ketone camphor. Secondary alcohols can be converted to ketones using very strong oxidizing agents such as chromic acid. In this…
1. Since Qualitative analysis is the method that used to known elements with unknown elements, by comparing and contrasting their properties, we can use this method in everyday life.
A. When we prepare our meal at home, we try to identify sugar to salt by testing.
B. At bank, we try to identify genuine banknotes to fake ones, by comparing their physical properties like watermarks paper quality and chemical properties which shows color changes when we put under UV light, but feck one does not charge…
sketch of the 3D geometry
Bonding pairs 2
Nonbonding pairs 2
Electron Geometry tetrahedral
Molecular Shape bent
Polar or NonPolar polar
Bonding pairs 3
Nonbonding pairs 1
Electron Geometry tetrahedral
Molecular Shape trig. pyramidal
Polar or NonPolar polar…
Arabic word meaning to surrender
Arabic word meaning one who submits to the will of God
Arabic word for God
One transcendent unlike anything in ordinary human experience
Misconception Allah as fierce or harsh
Rather Muslims focus on Allah’s mercy and gentleness
2) Pope / Patriarch
Patriarch – A Christian bishop of the early Church in certain major cities of the Roman Empire. This title is still in use in Eastern Churches today…