Atomic Structure Flashcards
What are the three sub-atomic particles that an atom contains?
Protons, neutrons and electrons
Where are protons and neutrons found?
In the nucleus in the centre of the atom
In an atom what other sub- atomic particle has the same number of charges as the protons?
Electrons
What happens when an atom loses one or more electron?
It becomes a positively charged ion
What happens when an atom gains one or more electron?
It becomes a negatively charged ion
What is the atomic number?
The number of protons in an atom
What is the mass number?
The total number of protons and neutrons in an atom
What two sub atomic particles have the same mass?
Protons and neutrons
How many electrons can the first, second and third shell hold?
2,8,8
What is electronic structure of an atom?
A description of how the electrons are arranged
When did John Dalton develop an atomic theory?
1800s
What was Daltons most important conclusions?
All matter is made of atoms
Atoms cannot be broken down into anything simpler
All the atoms of a particular element are identical to each other and different from the atoms of other elements
Atoms are rearranged in a chemical reaction
Compounds are formed when two or more different kinds of atoms join together
What did JJ Thomson discover?
The electron
What did Thomson show that Dalton didn’t?
The atom contained smaller pieces, whereas Dalton had thought that atoms could not be broken down into anything simpler.
What did Ernest Rutherford use experimental evidence to show?
An atom must contain a central nucleus
