Chapter 1 - Atomic structure Flashcards
Where does the word atom come from ?
The Greek word ‘atomos’
Who developed the plum pudding model and when ?
J.J Thomson in 1897
What was Rutherford’s theory about the atom ?
It had a positive core and negative electrons orbiting it
Who discovered the neutron ?
James Chadwick
How do you calculate the number of neutrons in an atom ?
mass number - atomic number
Why is an atom neutral ?
Because the number of protons equals the number of electrons
How many can the first shell of an atom hold and then subsequent shells ?
Two in the first shell and eight in subsequent.
What are isotopes ?
Isotopes are atoms of an element with the same atomic number but a different mass number, indicating a different number of neutrons.
what is the relative atomic mass ?
The relative atomic mass is a weighted mean of the mass numbers.
What is the radius of an atom ?
o.1 nanometres or 1 x 10^-10
what is the radius of an atoms nucleus ?
1 x 10^-14
What is the definition of an ion ?
An ion is a charged particle formed when an atom gains or loses electrons.
What is an anion ?
A negative ion
What is a cation ?
A positive ion
What is the definition of a compound ?
A compound is two or more elements chemically combined.
