Atomic Structure Flashcards
(47 cards)
What did daltons theory say about the structure of an atom
- All elements are made up of small invisible particles called atoms
- Atoms cannot be created or destroyed
- Atoms of different elements have different properties
- When atoms combine they form molecules or compounds
What did J.J. Thompson model of an atom look like
Plum pudding
Who discovered the electron
J J Thompson
Relative mass of proton
1
Relative mass of neutron
1
Relative mass of electron
1/1840
Relative charge of proton
+1
Relative charge of neutron
0
Relative charge of electron
-1
How to remember the relative charges
Neutrons= neutral
Protons= positive
Electrons= negative
Where are the protons and neutrons
Nucleus
Where are the electrons
In shells orbiting the nucleus
The shells can be filled by 2,8,8,8
What is an atom composed of
An atom is composed of a small dense positively charged nucleus at the centre composed of protons and neutrons (most of the mass) with negatively charged electrons in shells orbiting the nucleus.
Radius of an atom
0.1nm
What’s the atomic number
The number of protons in the nucleus of an atom
What’s the mass number
Total number of protons and neutrons in the nucleus of an atom
How do the atoms of one element differ to the atoms of another
The n.o. of protons, neutrons and electrons found in each atom are different
What is an element
A substance that consists of only one type of atom and it cannot be broken down into anything simpler by chemical means.
What’s the top number
Mass number
What’s the bottom number
Atomic number
How to find number of neutrons
Mass - atomic number
(Top - bottom)
The number of protons is equal to
The atomic number
Also the number of electrons
Where do the electrons go first
In the shell closest to the nucleus first.
Each shell must be filled with its full quota before starting to fill the next.
First has 2
The rest have 8
Ions
Atoms with electric charges
