topic 1 - key concepts and structure of the atom Flashcards
ammonia
NH3
ammonium
NH4 +
sulfate
SO4 2-
hydroxide
OH -
carbonate
CO3 2-
nitrate
NO3 -
hydrogen carbonate
HCO3 -
oxidising
provides oxygen, allowing materials to burn more fiercely
toxic
can cause death if ingested
highly flammable
catches fire easily
corrosive
destroys materials, including living tissues
environmental hazard
harmful to organisms and the environment
what is the role of risk assessments
they identify all hazards and their risks with likelihood and severity
ways to reduce/mitigate a risk are then considered
whoa re the 4 main scientists involved in the history of the atom
DALTON
JJ THOMSON
RUTHERFORD
BOHR
what did dalton say
described atoms as solid spheres
different spheres make up the different elements
what did jj thomson say
atoms are not solid spheres
they contain smaller, negatively charged articles (electrons)
e proposed the PLUM PUDDING MODEL ( a positively charged pudding and electrons stuck in it)
what was the gold foil experiment
rutherford conducted the gold foil experiment ; positively charged alpha particles were fired at a thin sheet of gold and instead of passing through or being slightly deflected, some were deflected more than expected or backwards ; THIS DISPROVED THE PLUM PUDDING MODEL
what did rutherford say
he proposed the nuclear model
this says that there is a positively charged nucleus with a high concentration of the atom’s mass and a cloud of negatively electrons surround it with lots of empty space around them
what did bohr say
scientists realised electrons in a cloud would be attracted to the nucleus, causing it to collapse
bohr proposed that electrons were arranged in energy levels which orbit the nucleus at a fixed radius and have a fixed energy
atomic number
how many protons an atom has
mass number
total number of protons and neutrons in an atom
isotope
different forms of the same element that has a different number of neutrons but the same number of protons
RAM
the average mass of one atom of an element compared to one twelfth of the mass of a carbon-12 atom
how to calculate RAM of isotopes
total isotope abundance
describe mendeleev’s periodic table
arrange known elements into groups according to their and their compounds properties
once organised according to increasing atomic mass, he found that those with similar chemical properties formed columns (some didn’t fit so were swapped or they didn’t fit because they has the wrong mass due to isotopes)
some gas were left for predicted by undiscovered elements
what is a group on the periodic table
columns with elements with similar chemical properties
what is a period on the periodic table
rows, each row represents another full shell of electrons
what do group and period tell you about electron structure
group tells you how many electrons there are in the outer shell
period tells you how many shells there are
