Atomic structure Flashcards
What was the first step of the atomic model?
John Dalton’s Solid Sphere Model in the early 1800s, that stated all atoms are tiny and invisible, all atoms on an element are identical and different elements have different types of atoms and atoms combine in fixed ratios to form compounds. However, this idea couldn’t explain electricity or subatomic particles
What was the second step of the atomic model?
JJ Thomson’s Plum Pudding Model in the late 1800s after he discovered the electron via cathode ray experiments, introducing the idea that atoms are positively charged spheres with negatively charged electrons scattered inside them. However, there was no nucleus in this model.
What was the third step of the atomic model?
Geiger and Marden’s Gold Foil Experiment in the early 1900s, where they fixed alpha particles at thin gold foil, expecting the particles to go through, yet some were deflected or bounced
What was the fourth step of the atomic model?
In the early 1900s, Ernest Rutherford invented the Nuclear Model, introducing the idea that atom is mostly empty space and there is a tiny positively charged nucleus at the centre made up of neutrons and protons and that electrons orbit the nucleus. However, it didn’t explain what stopped electrons spiralling into the nucleus
What was the fifth step of the atomic model?
Niels Bohr invented the Bohr Model in the early 1900s, introducing the idea that electrons orbit the nucleus in shells and can jump between levels by absorbing or emitting energy
What is an atom?
The smallest particle of an element
What is a proton?
Positively charged particle found at nucleus of atom
What is a neutron?
Particle with no charge found at nucleus of atom
What does the nucleus concentrate?
Nearly all of the atom’s mass
What is the nuclear and atomic radius?
1 times 10 to the -14 and 1 times 10 to the minus 10
What is relative charge?
Electrical charge of a particle compared to other subatomic particles
What is relative mass?
Mass of a particle compared to mass of a proton
Relative charge and mass of a proton?
Relative charge = +1
Relative mass = 1
Relative charge and mass of a neutron?
Relative charge = 0
Relative mass = 1
Relative charge and mass of a electron?
Relative charge = -1
Relative mass = 1/1836
What is an ion?
Charged particle formed when an atom loses or gains electrons
What is an atomic number?
Number of protons in nucleus of atom and number of electrons
What is a mass number?
Number of sum of protons and neutrons
What is an isotope?
Atoms with same number of protons, neutrons and electrons
How do you calculate the amount of neutrons in an atom?
Mass number minus atomic number
