atomic structure and bonding Flashcards
define the term atom
smallest particle of any matter that enters a chemical reaction
define the term element
a substance made up of only one type if atom
define the relative atomic mass
total number of neutrons and protons (nucleons) in an atoms nucleus
define the term atomic number
number of protons (and electrons) of an atom
define the term isotope
atoms of the same element with the same proton number but different nucleon number
why do isotopes share the same chemical properties
because they have the same number of electrons and chemical properties are determined by the number of electrons
why do isotopes of the same element have different physical properties
because they have different nucleon numbers
give 2 uses of radioactive isotops
U235 in nuclear power stations to release energy
cure cancer
define the term compound
substance made up of two or more atoms of the same or different element chemically bonded
define the term mixture
a substance made of two or more substances not chemically bonded only physically mixed
define the term ionic bonding
total transfer of electrons
define the term covalent bond
sharing of electrons
define the term metallic bond
attraction force between positive metal ions and electrons in metals
what force is found in ionic compounds
electrostatic
why do ionic compounds exist as solids (hard crystals)
due to strong electrostatic forces of attraction
why do ionic compounds have high mp and bp
due to strong electrostatic forces of attraction
why are ionic compounds soluble in water
water is able to form strong electrostatic forces with the ions, separating them
in which state do ionic compounds conduct electricity? explain your answer.
when molten or aqueous
due to the presence of free, mobile ions
all ionic compounds exist as (giant/simple) ionic compounds
giant
define the term lattice
3D regular arrangement of positive and negative ions
define the term covalent bonding
the sharing of electrons between two non metals resulting in the formation of a molecule
give 4 physical properties of simple covalent molecules
exist as liquids or gases
low mp and bp (due to weak intermolecular forces)
insoluble in water but soluble in organic solvents
dont conduct electricity (no free moving ions or electrons)
state the different between intermolecular and intramolecular forces
intermolecular is the weak force between molecules
intramolecular is the strong covalent bond between atoms
give another name for giant covalent molecules
macromolecules
