atomic structure and the periodic table Flashcards
what does the proton number tell you?
the number of protons
what does the mass number show?
the number of protons and neutrons added together
what is an ion?
atoms or groups of atoms that have gained or lost electrons so they will either have a positive or negative charge.
what is an element?
something made up of one type of atom
what is an isotope?
atoms of an element which have a different number of neutrons
how do you work out relative atomic mass?
sum of (isotope abundance x isotope mass number) / sum of abundances of all isotopes
what is a compound
a substance made from two or more elements chemically combined
what does diatomic mean?
two identical elements that combine, they are found in pairs
what does the name end in when two elements join
ide
what does the name end in when three or more elements combine and one of them is oxygen
ate
what does the name end in when three or more elements combine and two of them are hydrogen and oxygen
hydroxide
what does soluble mean?
a substance that dissolves in a liquid
define insoluble
a substance that does not dissolve in a liquid
define solvent
a liquid
define solute
a solid that dissolves into a solution
define solution
a liquid with a soluble solute dissolved in it
how do you work out the rf value?
distance from baseline to the spot / distance from the baseline to solvent front
what did thompsan discover?
protons
what is the plum pudding model?
a model that shows the atom as a ball of positivley charged with electrons scattered in it
what did rutheford do?
the alpha scattering experiment
Where did rutheford discover that the mass was
at center of the atom
what did bohr discover?
electrons are found in shells
how were elements previously catagorised in the first periodic table?
by chemical and physical properties and weight
how did mendeleev organise the periodic table?
in order of atomic mass
why did mendeleeve leave gaps in the periodic table?
for undiscovered elements
how is the modern periodic table organised?
proton number
what are elements in group 1 called?
alkali metals
are group 1 elements reactive?
yes
how many electrons do group 1 elements have on their outer shell?
1
what are group7 elements called?
hallogens
wha are elements in group 0 called?
nobel gases
what is ionic bonding?
between metals and non metals
do ionic compounds have a high or low mealting point
high
what is covalent bonding?
bonds between two non metals
how do covalent bonds get full outer shells?
sharing electrons from the outer shell
what is electrostatic attraction?
between positive and negative ions which hold them together
are cations positive or negative?
positive
are anions positive or negative?
negative
describe ionic compounds melting and boiling points
very high
can ionic compounds conduct electricity when they are solid?
no
what is a covalent bond?
between non metals
what is a simple molecular substance
a substance made up of molecules containing few atoms joined together by strong covalent bonds.
what is a intermolecular force?
forces between molecules
do simple molecules conduct energy?
no
what is a polymer?
a large molecule made from lots of covalently bonded smaller molecules
what is an allotrope?
alternative structural forms of the same elements in the same physical state
what is particle theory?
the theory we can model how solids liquids and gases
how can you tell if a substance is going to be a solid?
if the temperature is below the melting point
how can you tell if a substance is a gas?
it is above the boiling point
how can you tell if a substance will be a liquid?
if the temperature is between the melting and boiling point
what does the relative formula mass show?
how many protons and neutrons the atom has combined
how do you work out the percentage mass of an element in a compound?
ar of element x number of atoms of elements / mr of compound x 100
what is the Avogadro constant?
6.02x10 (ttp 23)
what is the ar?
relative atomic mass of element
what is the mr?
relative formula mass
what is the mole?
a measurement for chemical amounts
how do you work out the number of moles?
mass/relative atomic mass
