Clasified in Notes of Chemistry of Bachelor.
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Clasified in Summaries of Chemistry of Secondary.
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Solids have a definite shape and a definite volume. they are not motionless.
Types of Solids: Crystalline Solids and Amorphous Solids.
Crystalline regular and repeating, definite melting point. Amorphous are not repeating, softer when heated, no definite melting point.
Liquids have no definite shape, but a definite volume.
Viscosity Of Liquids: High viscosity liquids flow slowly, and low viscosity liquids flow quicker.
Gases: Move at high speed in all directions, can fill all space containers, no definite shape, nor volume.
State of Matter & Temperature: temperature can determine if its solid, liquid or gas.
Thermal Energy: particles a substance has because molecular motion, flow from warmer substance to cooler substance.
Clasified in Homeworks of Chemistry of University.
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Nailed shut:closed securely with nails and so imposible to open
Window sill: a ledge or shelf along the bottom of a window
Lightning rod:long,thinpiece of metal which attracts lightning and allows it to reach the ground safely
Hand-holds:small spaces where you can put your hands
Ethology:the science of animal behaviour
Advertisement:announcement in a newspaper
Ribbon:long narrow piece of cloth used for tying things
Go ape:become crazy
Swiping:hitting
Stable:buildings inwhich horses are kept
Reward:recompense for a service
Perpetrator:the person responsable for a crime
Shaving foam: a substance men put on their faces befote they shave
Alley:
Clasified in Notes of Chemistry of Bachelor.
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Clasified in Notes of Chemistry of Secondary.
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physical changes:composition doesn't change. chemical changes:substances change to form new substances with different properties.
COMPOUND: pure substance formed by two or more chemical elements always combined in fixed proportions, can break up using chemical methods into simpler substances. SIMPLE SUBSTANCE:is a pure substance formed by only one chemical element, can not break up into simpler substances using ordinary chemical methods.
Separation by chemical methods: thermal decomposition: chemical reaction whereby a chemical substance breaks up into at least two chemical substances when heated. light decomposition: light can decompose some compounds into other substances.
differences - homogeneous mixtures & compounds:
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Matter is anything made of atoms and molecules. Matter is anything that hs a mass and occupies a volume. Has general and characteristic properties ( boiling and melting temperatures). A material system is a piece of matter that can be separated for an experimental study. SOLID- fixed mass, volume and shape. They cannot flow.(ice,iron) LIQUID- fixed mass and volume. Variable shape. Can flow.(water,gasoline) GASEOUS- fixed mass. Variable volume and shape.They can flow.(co2,natural gas)
physical changes: composition doesn't change. chemical changes: substances change toform new substances with different properties.
SIMPLE SUBSTANCE: is a pure substance formed by only one chemical element, can not break up into simpler substances using ordinary chemical methods. COMPOUND: is a pure substance formed by two or more chemical elements always combined in fixed proportions.
... (Continue)Clasified in Summaries of Chemistry of Secondary.
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Q: volumen del fluido que atraviesa una sección transversal de una conducción por unidad de tiempo. P: Frepartida de forma homogénea en una superficie determinada.Compresor:maquina que comprime gases, transforma Em en Epresión, pueden ser alternativos o rotativos. Aternativos(intermitencia del aire comprimido): se clasifican en pistones en línea, en ángulo, en estrella y de membrana(construcción sencilla, membrana accionada por una biela montada en un eje motor excéntrico, se obtiene un movimiento de vaivén, producen aire comprimido exento de aceite, usados en medicina)Rotativos(aire comprimido a partir de mov.circular)tipos: de paletas(cámara cilíndrica y rotor cilíndrico con eje desplazado, al girar salen del rotor que crea compartimentos), de
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21 The greater the difference between the
electronegativity values of two elements
joined by a bond, the stronger
the bond.
22 Boron has three valence electrons.
Only three covalent bonds can form
around the central boron atom.
23 VSEPR theory helps to predict shape
based on how electron pairs orient
themselves around a central atom.
These electron pairs strive for orientations
that maximize the separations
between them. Two electron pairs give
a linear shape, three electron pairs a
trigonal planar shape, and four electron
pairs give a tetrahedral shape.
Clasified in Notes of Chemistry of Secondary.
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the protons and neutrons cluster together in the centre, forming the nucleus; this is the heavy part of the atom.
the electrons circlevery fast around the nucleus, at different energy levels from it.
ATOMS HAVE NO OVERALL CHARGE. the nº of neutrons doesn't affect the reaction in the nucleus.
when metals react with non-metals (metal atoms give electrons to non-metal atoms) form Ionic compounds: are made of crystals, have high melting points, are often soluble in water and conduct electricity when molten or dissolved in water, but not when solid.
the ions are arranged in huge strustures, called giant ionic lattices.
Ionic bounding: the oppositely charged ions are attracted to each other by strong electrostatic forces.
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redox reaction: when an electron transfer occurs and at least one element changes its oxdtn state. oxidation: procces in which electrons are lost, increasing the oxidtn state of that elemnt. reduction:process that involves a gain of electrons, decreasing the oxdtion state of the element. reductant: element that gets oxidized. oxidant: elemnt tht get reduced. redox couple: set cmposed by the oxidized and reduced forms of a determined specie. oxidation state: hypothetical charge an atom would have if all bonds to atoms of differentn elemnts were 100% ionic.
