Astronomy 10 Chapter 11 1. Both used to be normal stars but the white dwarf ran out of hydrogen, they are both subjected to gravitational theories. A Neutron star is a fluid of neutrons, as hot at its surface as the inside of the sun and has a greater magnetic field. 3. Because its density is so high, neutrons spin in the same way that electrons do so must obey the Pauli Exclusion Principle.
The process of changing one element into another is called transmutation. The two main ways that a transuranic nucleus can be produced is by bombarding its nucleus with ions or neutrons. These ions or neutrons can be captured by the target nucleus and produce heavier nucleus. Transuranic element 1: U-238 is bombarded with neutrons it can be converted to U-239 which then undergoes beta decay to produce neptunium and plutonium. Pu-239 is changed to americium-241 by neutron
______________________ 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.
Object A has a net charge of excess electrons. Object B is grounded. Which object is at a higher potential? A) A B) B C) Both are at the same potential. D) cannot be determined without more information Answer: B Diff: 2 Type: BI Var: 1 Page Ref: Sec.
The hydrogen molecule consists of two protons held together by a pair of electrons. These forces just balance when the nuclei are a particular distance apart. Co-ordinate bonding A single covalent bond consists of a pair of electrons shared between two atoms. In most covalent bonds, each atom provides one of the electrons. But, in some Bonds, one atom provides both the electrons.
high melting point, hard, brittle, slightly soluble in water, conductor of electricity when melted or in solution Molecular solid - crystalline solid that has molecules arranged in a particular configuration. low melting point, generally insoluble in water, nonconductor of electricity. Metallic solid - crystalline solid that has atoms of metals arranged in a definite pattern. low to high melting point, malleable, ductile, conductor of electricity, insoluble in most solvents. Lesson 13.6 Changes of physical state: * necessary to draw a temperature-energy graph to see the change in temperature with a constant application of heat Heat of fusion - the amount of heat required to melt 1.00 g of substance.
Seventy five percent of the table is made up of metals, and a couple of the columns on the right of the table have gases. There are only two elements that are liquids- mercury and bromine. Column 1 contains the alkali metals, which suddenly combust when exposed to air or water. Columns 3-12 are the transition metals, which contain heavier atoms, which are more flexible in how they organize their electrons. Column 17 is made up of the more reactive gases- the halogens.
A molecular orbital is merely a Schrödinger orbital which includes several, but often only two nuclei. If this orbital is of type in which the electron(s) in the orbital have a higher probability of being between nuclei than elsewhere, the orbital will be a bonding orbital, and will tend to hold the nuclei together. If the electrons tend to be present in a molecular orbital in which they spend more time elsewhere than between the nuclei, the orbital will function as an anti-bonding orbital and will actually weaken the bond. Electrons in non-bonding orbitals tend to be in deep orbitals (nearly atomic orbitals) associated almost entirely with one nucleus or the other, and thus they spend equal time between nuclei or not. These electrons neither contribute nor detract from bond strength.
Every row down the table is a group, of which there are eighteen. Elements in a group have their electrons arranged similarly, which makes the elements behave in similar ways. For example, group eighteen is called the Noble Gases because all of the elements in that group are gases that do not combine with any other atoms. Chemists use the periodic table to observe patterns and relationships between the elements. An example of this is that elements on the top left of the table are the most metallic and elements on the bottom right of the periodic table are the least metallic.
The element with the largest number of stable isotopes found in nature is tin, which has ten stable isotopes. All elements also have unstable isotopes, which are more susceptible to breaking down, or decaying, than are the other isotopes of an element. When atoms decay, the number of protons in their nucleus changes. Since the number of protons in the nucleus of an atom determines what element that atom belongs to, this decay changes one element into another. Different isotopes decay at different rates.