Atoms are the smallest basic units of matter, and are made of three subatomic parts. Protons, which are positively charged and identify the atom, are found in the nucleus. Then, there are neutrons; neutrons have no charge, and are also found in nucleus. This gives an atom it’s mass. Lastly, electrons are found on the energy rings and are negatively charged.
The simplest and most common element is Hydrogen, which can be in the form of a single proton, an extremely tiny particle with a positive charge. Sometimes electrons, even tinier particles, surround the proton, forming negatively charged shells. When two Hydrogen atoms link together, they form a Hydrogen molecule. Our sun, and all the other stars in the universe, are mostly made of the element Hydrogen. Trillions and Trillions of Hydrogen atoms are being smashed together in the sun and releasing energy which we feel as light and radiation.
13. Know definitions for the following terms: valence electrons (pg 26), nucleus (pg 26), atom (pg 26), element (pg 27), ion (pg 29), and chemical bond. (pg 28) 14. What are the basic subatomic particles (protons, neutrons, electrons)? (pg 26) Which of these are found in the nucleus?
Light can be considered as packets of energy called photons. A photon is a particle of electromagnetic radiation. Einstein found a very simple relationship between the energy of a light wave (photon) and its frequency: Energy of light = h × f Energy of light = (h × c)/λ Where h is a universal constant of nature called ``Planck's constant'' = 6.63 × 10-34 J/sec. All atoms have electrons. When electrons get excited they can jump from a low energy level to a higher energy level, as the electron can’t remain there, the electron de-excites and moves back to the lower energy level.
An atom containing an equal number of protons and electrons is electrically neutral, otherwise it is positively or negatively charged and is known as an ion. An atom is classified according to the number of protons and neutrons in its nucleus: the number of protons determines the chemical element, and the number of neutrons determines the isotope of the element. The name atom comes from the "indivisible", "not" and "I cut", which means uncuttable, or indivisible, something that cannot be divided further. The concept of an atom as an indivisible component of matter was first proposed by early Indian and Greek philosophers. In the 18th and 19th centuries, chemists provided a physical basis for this idea by showing that certain substances could not be further broken down by chemical methods, and they applied the ancient philosophical name of atom to the chemical entity.
Atoms consist of a positively charged nucleus with negatively charged electrons surrounding it. An ion is an atom or group of, that have lost an electron or more, making it even more charged and more reactive. A molecule is a particle of two or more atoms held by chemical bonds. Its the smallest of units and exists independently. C. Define the term nutrient, and outline the main groups of nutrients.
CHAPTER 10 - Radioactivity and Nuclear Processes Composition of atomic nucleus - neutrons and protons Nuclides are nucleus of different isotopes, which is represented by the symbol [pic]X - X being symbol of the element. A is the mass number, which is the sum of number of protons & neutrons; Z is the atomic number, the number of protons, which also represents the nuclear charge. Number of neutrons = (A – Z). For example, the symbol of carbon-14 nuclide is [pic]C, which means a carbon-14 nuclide has 6 protons and 8 neutrons. The nuclide symbol of lead-206 is [pic]Pb.
Nuclear fusion and nuclear fission are two different types of energy-releasing reactions in which energy is released from high-powered atomic bonds between the particles within the nucleus. The main difference between these two processes is that fission is the splitting of an atom into two or more smaller ones while fusion is the fusing of two or more smaller atoms into a larger one. Nuclear fission is a class of nuclear change. Nuclear fission occurs when a very heavy nucleus splits into two smaller nuclei, each more stable than the original nucleus. Most fission reactions happen artificially by bombarding nuclei with neutrons.
______________________ neutral 0 b. ______________________ negative c. ______________________ 2. The number of protons in one atom of an element determines the atom’s idenity ______________________ , and the number of electrons determines charge ______________________ of and element. 3. protons The atomic number tells you the number of ______________________ in one atom of an element. It also tells you the number of ______________________ in a neutral atom of that electrons element.
All the matter we see around us are composed of different types of atoms. Deep in the heart of each atom there is the nucleus, which is composed of yet smaller particles, protons and neutrons (nucleons). Their behavior is controlled by three fundamental forces of nature – the strong force, together with the weak and electromagnetic forces. These forces combine to generate highly complex nuclear structures that are challenging to study and understand. This complex structure and energy based force is responsible for the large scale energy emission.
5. 5. II. Mass Defect and Nuclear Binding Energy Consider a helium-4 atom: (_______ protons, _________ neutrons, and __________ electrons) Recall: 1 proton = 1.007277 u, 1 neutron = 1.008665 u, and 1 electron = 0.000548 u We would expect the mass of a helium-4 atom to be as follows: 2(1.007277 u) + 2(1.008665) + 2(0.000548) = 4.032980 u However the observed mass of a helium-4 atom is 4.002596 u!!!!!! There is a difference of 0.030384 u between the observed mass and the calculated mass.
Physics THE NUCLEUS The atomic nucleus consists of nucleons—protons and neutrons. Protons and neutrons are made of quarks and held together by the strong force generated by gluon exchange between quarks. In nuclei with many nucleons, the effective strong forces may be described by the exchange of mesons (particles composed of quark-antiquark pairs). A proton consists of two up quarks and one down quark along with short-lived constituents of the strong force field. A neutron is similar except that it has two down quarks and one up quark.
1. What three particles make up every atom? • Electron- negatively charged Proton-positively charged Neutron_electrically neutral 2. What are the major differences among the three particles that make up every atom? • The electron, the proton and the neutron are the "building blocks" of the atom.
The nucleus is surrounded by circling electrons on the outer shell. In most cases, atoms are neutrally charged (there is the same number of electrons as protons). If an atom has more electrons than protons, it is negatively charged. If an atom has more protons than electrons, it is positively charged. Static electricity is produced from a process known as triboelectrification.
The Atomic Mass of Candium Introduction: An atom is the smallest particle of an element that retains its identity in a chemical reaction. Atoms are made up of three different particles, protons, neutrons, and electrons. The atomic mass is the total mass of the protons, neutrons, and electrons in a single atom when it is at rest. The purpose of this experiment is to find the atomic mass of Candium. Isotopes are that have the same number of protons but different numbers of neutrons; therefore they have different mass number.
Atoms are made up of three particles. They are the proton (which is the positively charged particle), electron (which is the negatively charged particle), and the neutron (which has no charge at all). Ions are just an atom that has lost or gained an electron. An atom is the most stable but only when it outer most layer is filled. Isotopes- are atoms of the same element but different number of neutrons.
Atoms of the same element that differ in mass number are called isotopes. Since all atoms of a given element have the same number of protons in their nucleus, isotopes must have different numbers of neutrons. Helium, for example, has an atomic number of 2 because of the two protons in its nucleus. But helium has two stable isotopes—one with one neutron in the nucleus and a mass number equal to three and another with two neutrons and a mass number equal to four. Scientists attach the mass number to an element’s name to differentiate between isotopes.
The Atomic Structure The atomic structure is the structure of an atom, theoretically consisting of a positively charged nucleus surrounded and neutralized by negatively charged electrons revolving in orbits at varying distanced from the nucleus, the constitution of the nucleus and the arrangement of the electrons differing with various chemical elements. Over time, the atomic structure has been changed or even interpreted differently. For example, some people thought that there was no positive or no negative in the atom, meanwhile some people thought that there was. Some thought that there were fixed paths between the positive and negative charges (meaning the proton or electron), others thought that they were randomly placed in the atom. Some model’s created over time were by famous people such as Dalton, Thomson, Rutherford, Bhors, and what we have now which is the wave mechanical method.
The Atomic Structure The atomic structure is the structure of an atom, theoretically consisting of a positively charged nucleus surrounded and neutralized by negatively charged electrons revolving in orbits at varying distanced from the nucleus, the constitution of the nucleus and the arrangement of the electrons differing with various chemical elements. Over time, the atomic structure has been changed or even interpreted differently. For example, some people thought that there was no positive or no negative in the atom, meanwhile some people thought that there was.The nucleus has more than 100 protons and more than 150 neutons, the nucleus is a very small part of an atom. Both the atom and the necleus can be thought of as spheres. Then both volumes of the atom can be compared with the volume of the nucleus alone, because the volume of a sphere is proportionalb to the cube of its radius.The space outside the nucleus is occupied only by electrons.
INTRODUCTION TO NUCLEAR REACTION: The main features of nuclear reactions include radioactive decay, nuclear fission and nuclear fusion. Radioactive decay: Energy is released in a radioactive decay in the form of the kinetic energy of the particle emitted (α and β), the kinetic energy of the daughter nucleus and the energy of the gamma-ray photon that may accompany the decay. The energy involved may be calculated by finding the mass defect of the reaction. The energy released is the energy equivalent of the mass defect of the reaction. Nuclear fission: Nuclear fission is the process in which a large nucleus breaks into two smaller nuclei that are almost equal in mass.