Topic 1 - particles Flashcards
electrons
Sub-atomic particles of negligible mass that orbits the nucleus of an atom. Electrons are negatively charged.
neutrons
Sub-atomic particle with a mass of one found in the nucleus of an atom. A neutron has zero charge.
protons
Positively charged sub-atomic particles found in the nucleus of an atom. Protons have a mass of 1.
nucleus
The positively charged centre of the atom consisting of protons and neutrons that contains almost all the mass of the atom.
proton number
The number of protons found in the nucleus of an atom. The number of protons in its nucleus defines an atom. Also called the atomic number.
isotopes
Atoms of the same element so they have the same proton number but with different numbers of neutrons (nucleon number).
nucleon
The combined number of protons and neutrons in the nucleus of an atom. The nucleon number also represents the mass of an atom and is also known as the mass number.
mass number
The combined number of protons and neutrons in the nucleus of an atom. The mass number also represents the mass of an atom and is also known as the nucleon number.
group
A term used in chemistry to describe a column in the Periodic Table. The elements within a group have similar chemical properties as they all have the same number of electrons in the outer shell.
period
A term used in chemistry to describe a horizontal row in the Periodic Table. The period number tells you how many electron shells an element has.
how to find mass/nucleon number
mass number = number of protons + number of neutrons
how to find the amount on neutrons
number of neutrons = mass number − proton number
electronic configuration
The distribution of electrons of an atom or molecule in electron shells.
ions
An electrically charged particle formed when an atom either loses or gains electrons.
radioactive
The property of unstable nuclei that break down and release energy and different forms of radiation.
nuclear notation
A method of displaying the key data of an element and its isotopes. The symbol for the element is preceded by the proton number (bottom) and nucleon number (top).
ionic bonding
Chemical bonding that occurs when metals transfer electrons to non-metals to form ions.
Cation
Positively charged ions.
Anion
Negatively charged ions.
Dot and cross diagram
A method to demonstrate the electronic configuration of ions and compounds.
Strong electrostatic forces
The powerful attractive force between oppositely charged particles. Either formed when anions and cations pull together to form ionic bonds, or by the pull between positive nuclei and the shared pairs of electrons in covalent bonds.
Ionic bond
A force of attraction between a cation and anion.
Giant lattice structures
Three dimensional structures in which the positive and negative ions of ionic compounds are held together by strong electrostatic forces.
Do ionic compounds conduct electricity?
ionic compounds do not conduct electricity as solids
ionic compounds are good conductors of electricity when heated strongly to become molten liquids
ionic compounds are good conductors of electricity when dissolved in water.
non-metal
An element that is not a metal. Tends to accept electrons during reactions.
noble gas configuration
When an atom achieves a full outer electron shell, which is a highly stable configuration. This can occur either through ionisation or sharing electrons through covalent bonding.
single bond
A covalent bond in which one pair of electrons are shared.
double bond
A covalent bond in which two pairs of electrons are shared.
triple bond
A covalent bond in which three pairs of electrons are shared.
intermolecular forces
The weak force of attraction that holds molecules close together.
macromolecule
A giant molecule created by atoms covalently bonded to one another.
Mohs scale
A scale that ranks the hardness of naturally occuring minerals from 1 to 10. 1 is talc, the softest material. 10 is diamond, the hardest material.
allotropes
Alternative forms of an elemental substance. For example, diamond and graphite are allotropes of carbon.
delocalised
Electrons that are not associated with a particular atom.
mixture
Two or more chemical substances found together but not chemically bonded.
Carbon monoxide
A toxic gas containing equal parts of carbon and oxygen. An air pollutant formed by the incomplete combustion of carbon-containing fuels.
Organic compound
A substance consisting of carbon and one or more other elements, joined together by covalent bonds.
Word endings for four different homologous series.
Suffix Homologous series
–ane alkanes
–ene alkenes
–ol alcohols
–oic acid carboxylic acids
Alcohols
An organic compound that contains an OH functional group.
carboxylic acid
An organic compound containing a –COOH functional group.
Prefixes that show the number of carbon atoms present.
Prefix Number of C atoms
meth 1
eth 2
prop 3
but 4
fuel
A type of substance that stores energy.
hydrocarbons
A compound made of hydrogen and carbon only.
petroleum
The mixture of hydrocarbons found naturally formed by the decay of marine organisms. Also known as crude oil.
molecular formula
A symbol formula that identifies the actual amount of each atom in a molecule or compound.
reactants
The substances that exist at the start of a chemical reaction. In a symbol equation, reactants are shown on the left-hand side.
products
The substances formed during a chemical reaction. In a symbol equation, products are shown on the right-hand side.
A word equation
Display of a chemical reaction using the names of the reactants and products.
symbolic equation
Display of a chemical reaction using the elemental symbols of the reactants and products.
polyatomic ion
An molecular ion that consists of atoms of more than one element that are covalently bonded together.
Balanced equation
A symbol equation that shows that for every element present there is an equal amount of atoms on both sides of the equation.
aqueous
A substance (solute) dissolved in water.
ionic equation
A symbol equation that only shows the atoms and ions that react together.
relative molecular mass
The sum of the relative atomic masses of the elements within a compound or molecule. Symbol Mr.
relative atomic mass
The average mass of an element on a scale in which the carbon-12 atom has a mass of exactly 12u. Symbol Ar.
Balanced symbol equation
A symbol equation that shows that for every element present there is an equal amount of atoms on both sides of the equation.
Avogadro constant
The number of particles in one mole of a substance. Has the value of 6.022×1023.
molar mass
The mass of one mole of a compound, calculated by dividing the mass by the number of moles present. Units g/mol.
The amount of a substance in moles (mol) can be calculated from its mass using the formula:
mount of substance (mol) = mass (g) / molar mass (g/mol)
Solute
A soluble solid that has dissolved in a solvent.
Solvent
A liquid substance within which a solid can dissolve.
Concentration can be expressed in grams per decimetre cubed (g/dm3 ) and can be calculated using the equation:
concentration (g/dm3)= mass (g) / volume (dm3)
Molar concentration
The concentration expressed in moles of a solute per unit volume of solution.
Units mol/dm3 .
titration
Method used to determine the concentrations of two solutions that exactly react with one another.
Molecular formula
A symbol formula that identifies the actual amount of each atom in a molecule or compound.
Empirical formula
The simplest whole number ratio of atoms in a compound or molecules.
