Glossary a-e Flashcards
absorbance
the ability of a substance to absorb a certain wavelength of light
absorption line
The black lines found in a continuous spectrum of light
accuracy
how close to the real value a measurement is
acid (Arrhenius)
a substance that can make hydrogen ions in solution
acid (Bronsted-Lowry)
a substance that can donate a hydrogen ion (proton)
acid - base reaction
- when and acid reacts with a base.
* may be called Neutralization when in correct proportion.
acid rain
rainwater that reacted with acidic gases in the atmosphere to make water with a pH of less than 5.5
acidic solution
a solution which has more hydrogen ions than hydroxide ions.
pH is < 7
acidity
the concentration of H+ ions in a solution.
What scale measured the acidity of a solution?
pH scale
activation energy
the minimum energy the reactants require for the reaction to occur.
What is the symbol for activation energy?
Ea.
What is the activation energy needed for?
To break the bonds between atoms in the reactants
active site
the specific part of an enzyme molecule where the reactant can interact
addition reaction
a reaction in which a molecule binds to an unsaturated hydrocarbon (alkene, alkyne) to form a single carbon bond.
How many products are formed in an addition reaction?
1
adsorption
when a substance sticks to the surface of a liquid or a solid
alkali
a soluble base
alkali metal
a group 1 metal.
alkane
a saturated hydrocarbon with all single bonds
What is the general formula for a straight alkane
Cn H(2n+2)
alkene
an unsaturated hydrocarbon with a double bond between carbons.
alkyl group
a hyrdocarbon group on main carbon chain
alkyne
an unsaturated hydrocarbon with a triple bond between .carbons.
allotrope
different forms of the same element in which the atoms are bonded in different ways
Allotropes of carbon
graphite, diamond
Allotropes of oxygen
oxygen gas, ozone gas.
alloy
a mixture of a metal an another substance like C or another metal/s.
An alloy of copper and tin
bronze
An alloy of copper and zinc
brass
An alloy of iron and carbon
steel
alpha particle
a positively charged particle in radiation, similar to a helium nucleus
amorphous
a substance with no consistant structure
anion
a negatively charged ion
annealing
heating a metal to a moderate temperature and letting it cool slowly. This makes the metal softer and more ductile.
What effect does annealing have on a metal?
It makes it softer and more ductile.
aqueous (aq)
A substance is dissolved in water.
i.e. water is the solvent.
Arrhenius model - acid
It defines an acid as a substance that ionizes in water to produce hydrogen ions (H+) or protons.
Arrhenius model - base
It defines a base as a substance that dissociates in water to form hydroxide OH- ions
artesian basin
an underground area of porous rock that stores water.
asymmetrical molecule
a molecule in which the polar bonds are unevenly distributed.
asymmetrical molecule 2
dipoles
the bond dipoles do not cancel and and overall dipole is created.
atom
The basic building block of matter.
Smallest particle of an element.
What particles make up an atom?
Made of protons and neutrons in the nucleus.
Surrounded by electrons in shells.
atomic absorption spectroscopy (AAS)
A technique that uses light absorption to measure the amount of metal in a sample.
atomic number
The number of protons in the nucleus of an atom.
What is the symbol of the atomic number?
Z
atomic radius
A measurement of the size of an atom, half the distance between adjacent atoms in a molecule
atomic theory of matter
states all matter is made up of atoms.
Atoms are indivisible and elements are made of identical atoms.
Avogadro’s Law
At the same temperature and pressure equal volumes of all gases contain equal numbers of particles.
Avogadro’s number
the number of particles in a mole.
6.023 x 10 23
bar
unit of pressure
base (Arrhenius)
a substance capable of producing hydroxide ions.
base (Bronsted-Lowry)
a substance capable of accepting a proton.
a basic solution
an aqueous solution with more hydroxide ions than hydrogen ions.
What is the pH of a basic solution?
pH is greater than 7
bias
values skewed in one direction from the true value.
e.g. too high or too low.
biodegradable
capable of being broken down by bacteria
biofuel
fuel made from plants such as grains, sugar or vegetable wastes and oils.
bohr diagram
a simple diagram that shows the arrangement of electrons around the nucleus.
Bohr Model of the Atom
a theory of the atom by Niels Bohr where electrons occupy fixed, circular orbits.
bore water
water that comes from underground
brittle
shatters when given a sharp tap.
buckyball
a ball like structure of carbon atoms.
calibrate
to check the scale of an instrument
calibration curve
a graph of two variables that can be used to determine the true value of one of the variables