Atomic Structure And The Periodic Table. Flashcards
Name the particles that are found in the nucleus of an atom.
Protons and Neutrons
What is the charge of a proton, neutron and electron?
Proton: +1
Neutron: 0
Electron: -1
What is the relative mass of a proton?
1
What is the relative mass of a neutron?
1
What is the relative mass of an electron?
0 (negligible)
What is the overall charge of an atom?
0, atoms have no overall charge because they contain an equal number of protons and neutrons.
What does the ‘atomic number’of an atom tell you?
The number of Protons the atom has.
What does the ‘ Mass number ‘ of an atom tell you?
The sum of the protons and neutrons the atom has.
How can you use the atomic number and mass number of a given atom, to work out how many neutrons it has?
Number of neutrons = mass number - atomic number
What is an element?
An element is a substance made up of only one type of atom, so where all atoms of a substance have the same number of protons.
What is an isotope?
Isotopes are different forms of the same element, which have the same number of protons but different number of neutrons.
Describe the history of the atom.
-1803, Dalton described atoms as solid spheres
- 1837, JJ Thomson discovered the electron and then created the Plum Pudding model.
-1909, Rutherford did the gold foil experiment
-1913, The Bohr model has electrons in shells.
What is relative atomic mass?
The relative atomic mass of an element is an average value that takes account of the abundance of the isotopes of the element.
How to calculate relative atomic mass of an element given the percentage abundance of its isotopes?
Ar = (mass number of isotope 1 X percentage abundance of isotope 1) + (mass number of isotope 2 X percent abundance of isotope 2) / 100
How was Mendeleev’s periodic table arranged?
Into order of atomic mass, so that elements with similar properties would be in groups.
This enabled him to predict the properties of undiscovered elements.
He left gaps to predict undiscovered elements
