C1 - The Atom (PAPER 1) Flashcards
What is an atom
the smallest part of an object that can exist
What is Dalton’s model of the atom
atoms as solid spheres that could not be divided into smaller parts
What is the plum pudding model of the atom
sphere of positive charge with negative electrons embedded in it
What did scientists discover in the alpha scattering experiment
some alpha particles were deflected by the gold foil - this showed that an atom’s mass and positive charge must be concentrated in one small space (the nucleus)
Describe the nuclear model of the atom
dense nucleus with electrons orbiting it
What did Niels Bohr discover
electrons orbit in fixed energy levels (shells)
What did James Chadwick discover
neutron
Where are protons and neutrons
in the nucleus
What is the relative mass of each particle
proton = 1
neutron = 1
electron = 0
What is the relative charge of each particle
proton = 1
neutron = 0
electron = -1
How can you find the number of protons in an atom
the atomic number on the Periodic table
How can you calculate the number of neutrons in an atom
mass number - atomic number
Why do atoms have no overall charge
equal number of protons and electrons
How many electrons can go in 1st, 2nd and 3rd shells
1st = up to 2
2nd & 3rd = up to 8
What is an element
substance made of one type of atom
