Chemistry Element – pure substances that cannot be broken down Into simpler substances. Made up of particles/atom of only one kind. Simplest pure substances. ; Compounds – pure substances which contain two or more different elements. ; Atom – smallest particle of an element. The smallest unit of an element that maintains the properties of that element. ; Chemical Group – the set of elements in the same column of the periodic table. These elements have similar physical and chemical Isotope – An isotope of an element has different number of neutrons. Properties. ;
Radioisotopes – Some Isotopes are unstable, which means that the nucleus has a tendency to break apart and eject particles. Atoms that have unstable nucleus are called radioisotopes. ; Subatomic particles – the particles of which an atom is made of are the subatomic particles. ; Excited state – When electrons are energize by heat, electricity or light, they use the extra energy tossup in an higher orbit. ; Ground state – low-energy state of an electron. Spectrum -a rainbow of many colors that combine to make white light. ; Molecule – Atoms Join together to form molecules.
Corrosion – the slow chemical change that occur when a metal reacts with oxygen to form a new substance – oxide. ; Combustion – substance reacts rapidly with oxygen, releasing large amounts of energy. ; Atomic Number – the number of protons in an atom. Mass Number – the sum of protons and neutrons in the nucleus of an atom. ; Precipitate – a solid, Insoluble material that forms In a liquid solution. Properties of Matter Malleability – ability of a substance to be hammered or bent into deferent shapes. Ex: Aluminum foil. ; Viscosity -a measure of how easily a liquid flows.
The thicker the liquid, the more viscous it is. ; Ductility – ability to be drawn into thin wires. Ex: Luster – quality or state of shining. Ex: Gold. Copper. ; Density – amount of matter per unit volume. Measured In keg/cam, g/cam, WI or g/ ml. ; Meteor – a bright streak of light caused by a meteoroid. ; crystal Form – forms of minerals in which you can see a definite structure of cubes or blocks with patterns. ; Hardness – resistance off solid to being scratched or dented. ; Solubility – ability of a substance to dissolve in a solvent. ; Asteroid – small rocky abject. Universe Comet – a chunk of Ice and dust that revolves In a very long orbit around the Sun. Planet – a large piece of matter, generally spherical, that revolves around a star. ; Constellation -a group of stars that form shapes or patterns. ; Solar System – the Sun and all the objects that travel around it, including nine known planets and the moons of those planets. ; Universe – everything that exists including all matter and energy. ;Model – a way to represent something. Revolution – movement of an object traveling around another object. ; Rotation – Galaxy -a huge collection of gas, dust with billions of stars and planets. Black Hole – the high-density core left when a star approximately 30 times the mass of the Sun dies. ; Nebula -a huge cloud of dust and gases in outer space. ; White Dwarf- a small star created by the remaining materials when a red giant dies. ; Black Dwarf – Red Giant – Stars in their old age become larger and red. Stars the size of the Sun, become red giants. ;Super giants – Stars with mass about 10 times larger than the Sun become super giants. ; Neutron Star – When a star about 10 times the mass of he Sun dies, the resulting core is called a neutron star – an extreme star composed of neutrons. Corona – the hot outer part of the Sun. Chromospheres – the inner atmosphere of the Sun. Solar prominence – large sheets of glowing gases bursting outward the chromospheres. ; Photosphere – surface of the Sun made of churning gases. ; flare – travel outward from the chromospheres. Core – core of the Sun where nuclear fusion produces energy. Pressure is Solar Telescope – an object helpful to study objects in the solar system. ; enormous. ; Light Year – the distance traveled by light in one year. Astronomical Unit (A.
U) – distance measurement used by astronomers to compare large distances in the Solar System. 1 A. U = distance between Earth and the Sun. ; Terrestrial Planets – the four planets close to the Sun. These planets resemble Earth so they are called terrestrial planets. They have density roughly same as the density of rock. ; Gas Giants – the outer planets which are large, and their atmosphere mainly consists of helium and hydrogen, which have low densities. Gas Giants appear to lack solid surfaces. ; Meteor – a bright streak of light caused by a meteoroid.