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Chemistry Test 1
Chapters 1 & 2
Question | Answer |
---|---|
Physical property | observed with the senses |
Physical change | a change in size, shape, or state;no new substance |
Chemical property | indicates how a substance will react with something else; matter will be changed into new substance |
Chemical change | a change in the chemical and physical properties; new substance is formed |
Kelvin= | Celsius + 273 |
Celsius= | Kelvin - 273 |
exothermic | releases heat |
endothermic | process absorbs heat and cools the surroundings |
chemical reaction | a process that involves rearrangement of the molecular or ionic structure of a substance, as opposed to a change in physical form |
product | The substances that result from this recombination of atoms |
reactant | written on the left side, in a similar manner to a math equation |
density | Density is the mass of a substance per unit volume. |
mass | Mass is a measure of the amount of matter in a substance or an object. |
matter | Matter is all the “stuff” that exists in the universe. |
quantity | the amount or number of a material or immaterial thing not usually estimated by spatial measurement. |
volume | the amount of space that a substance or object occupies, or that is enclosed within a container, especially when great. |
weight | the name of the force exerted on an object due to the acceleration of gravity. |
allotrope | each of two or more different physical forms in which an element can exist. Graphite, charcoal, and diamond are all allotropes of carbon. |
atom | the smallest component of an element, characterized by a sharing of the chemical properties of the element and a nucleus with neutrons, protons and electrons. |
element | a substance whose atoms all have the same number of protons |
molecule | a complete chemical unit |
acid | A substance that produces H+(aq) ions in aqueous solution. Strong acids ionize completely or almost completely in dilute aqueous solution. Weak acids ionize only slightly. |
base | A substance that produces OH (aq) ions in aqueous solution. Strong soluable bases are soluble in water and are completely dissociated. Weak bases ionize only slightly. |
compound | A substance of two or more elements in fixed proportions. Compounds can be decomposed into their constituent elements. |
mixture | A sample of matter composed of two or more substances, each of which retains its identity and properties |
ion | An atom or a group of atoms that carries an electric charge. |
inorganic compound | any compound that does not both carbon and hydrogen together |
organic compound | any compound that contains both carbon and hydrogen together |
pH | a figure expressing the acidity or alkalinity of a solution on a logarithmic scale on which 7 is neutral, lower values are more acid, and higher values more alkaline. |
chemical bond | The attractive forces that hold atoms together in elements or compounds. |
energy | The capacity to do work or transfer heat. |
heat | the sum of the total of kinetic energy of the particles in a sample of the matter |
kinetic energy | energy a moving object has because it is in motion |
potential energy | energy an object has because of its location |
specific heat | the amount of heat energy required to raise the temperature of 1g of a substance by 1 kelvin |
system | an integrated whole, composed of diverse, interacting, specialized structures and subfunctions. |
temperature | A measure of the intensity of heat |
hypothesis | a testable question/problem |
theory | a supposition or a system of ideas intended to explain something, especially one based on general principles independent of the thing to be explained. |
scientific law | statement based on repeated experimental observations that describes some aspect of the universe. |
accuracy | How closely a measured value agrees with the correct value. |
precision | how close multiple results are to each other |
solid | definite shape/volume - molecules tightly packed - vibrate in place |
liquid | definite volume; variable shape - moderately packed - flow over each other |
gases | indefinite shape/volume - spread far apart - rapid random motion |
reactants | to the left of the arrow |
products | to the right of the equation |
KHDBDCM | kilo, hecto, deka, base, deci, centi, milli |
density = | mass/volume |
heterogeneous mixture | can be separated from one another. |
homogeneous mixture | a solid, liquid or gaseous mixture that has the same proportions of its components throughout a given sample |
activation energy | the amount of energy needed to make an object begin movement |
law of conservation of energy | energy can neither be created nor destroyed |
% of error= | theoretical-experimental / theoretical X 100 |