# data[].attributes.body
Electron (negative)

Proton (positive)

Neutron (no charge)

# data[].attributes.body
Cathodes → minus sign —

Anodes → plus sign +

# data[].attributes.headline
Can atoms be broken down into simpler atoms?

# data[].attributes.subject
Can atoms be broken down into simpler atoms?

# data[].attributes.headline
First discovery that atoms can be broken down -

# data[].attributes.subject
First discovery that atoms can be broken down -

# data[].attributes.body
The electron which JJ Thompson discovered in 1897 showed that atoms contain smaller particles.

# data[].attributes.headline
Atoms are made of even smaller particles -

# data[].attributes.subject
Atoms are made of even smaller particles -

# data[].attributes.body
Experimental evidence - used by Ernest Rutherford in 1911 - shows that an atom must contain a central nucleus.

This was further evidence that an atom contains smaller particles and can be broken down.

# data[].attributes.body
-Atoms are made of even smaller particles
-Unlike charges attract and like charges repel
-Nuclues is much heavier than alpha particle itself
-Nucleus is incredibly heavy, over 99% of the atom's weight is concentrated and is incredibly small
-Rutherhood discovered a particle inside a nucleus, which is responsible for its positive charge➡️proton
-James Chadwick➡️discovered a new particle➡️had no charge because they are electrically neutral➡️neutrons

# data[].attributes.headline
Experimental evidence to further support Rutherford’s nuclear atom idea -

# data[].attributes.subject
Experimental evidence to further support Rutherford’s nuclear atom idea -

# data[].attributes.body
Electrons occupy particular orbits or shells around the nucleus of an atom.

# data[].attributes.body
John Chadwick discovered the neutron in 1932, and realised that most of the mass was double the number of protons.

# data[].attributes.headline
Why is most of the mass of an atom double the number of protons?

# data[].attributes.subject
Why is most of the mass of an atom double the number of protons?

# data[].attributes.body
Where the electron cloud is most dense, the chance of finding the electron is greatest.

# data[].attributes.body
All matter is made of atoms

# data[].attributes.body
Thompson- found out that atoms could be broken down into sub-atomic particles
Rutherford- central nucleus in positive charge which is surrounded by a cloud of negative charges
Bohr- thinks that electrons surround central nucleus in orbits; electrons are fixed in position in electron shells (1913)
Chadwick- the mass of the atom is double of mass of protons
Schrödinger- used mathematical equations to describe the likelihood of finding an electron in a certain position ; nucleus contains protons and neutrons; electron cloud surrounding it
A=10^-10
Proton: 1.672623 x 10-27
Electron:9.109390 x 10-39

# data[].attributes.headline
Atoms cannot be broken down into anything simpler

# data[].attributes.subject
Atoms cannot be broken down into anything simpler

# data[].attributes.headline
Used experimental evidence to show that an atom must contain a central nucleus. This was further evidence that an atom contained smaller peices

# data[].attributes.subject
Used experimental evidence to show that an atom must contain a central nucleus. This was further evidence that an atom contained smaller peices

# data[].attributes.headline
All the atoms of a particular element are identical to each other 

# data[].attributes.subject
All the atoms of a particular element are identical to each other 

# data[].attributes.headline
Niels Bohr used experimental evidence to support the idea that electrons occupy particular orbits or shells around the nucleus of an atom

# data[].attributes.subject
Niels Bohr used experimental evidence to support the idea that electrons occupy particular orbits or shells around the nucleus of an atom

# data[].attributes.headline
Use relative atomic mass to find out mass of atom

# data[].attributes.subject
Use relative atomic mass to find out mass of atom

# data[].attributes.body
Dalton-Atoms
Thompson- Electrons
Rutherford- Central nucleus /protons
Chadwick- neutrons in nucleus
⭐️ Bohr- electron shells
Sub-atomic particles ➡️Protons
➡️Neutrons ➡️ Electrons

# data[].attributes.body
Protons and neutrons contributes to mass of atom
Atoms are electrically neutral
Number of protons equals to number of electrons for atoms only

# data[].attributes.body
Dalton-atoms
Thompson-electrons
Rutherford-nucleus/protons
Bohr-electron shells (electron orbits)
Chadwick-neutrons

# data[].attributes.headline
Which is heaviest - proton, neutron or electron?

# data[].attributes.subject
Which is heaviest - proton, neutron or electron?

# data[].attributes.body
For the above diagram

# data[].attributes.headline
ISOTOPES-atoms of the same element with the same number of protons but different number of neutrons

# data[].attributes.subject
ISOTOPES-atoms of the same element with the same number of protons but different number of neutrons

# data[].attributes.body
They have the same number of positive and negative charges.

# data[].attributes.body
SI unit for mass is kg

# data[].attributes.body
1)atoms of the same element
2)with the same number of protons
3)different number of neutrons

# data[].attributes.headline
Number of protons = Number of electrons 

# data[].attributes.subject
Number of protons = Number of electrons 

# data[].attributes.body
Atoms of the same element(Boron)
With the same number of protons(5)
Different number of neutrons(Boron-10 has 5 neutrons a Boron-11 has 6 neutrons)

# data[].attributes.body
Mass number - number of protons

# data[].attributes.body
Dot-and-cross diagram

# data[].attributes.headline
Why is Hydrogen separated from the rest of the atoms in the Periodic table?

# data[].attributes.subject
Why is Hydrogen separated from the rest of the atoms in the Periodic table?

# data[].attributes.headline
Number of electrons = Number of protons(only for atoms)

# data[].attributes.subject
Number of electrons = Number of protons(only for atoms)

# data[].attributes.headline
The Roman number on the top of the Periodic table represent the number of electron in the outermost shell

# data[].attributes.subject
The Roman number on the top of the Periodic table represent the number of electron in the outermost shell

# data[].attributes.headline
Same row will have the same number of occupied electron shell

# data[].attributes.subject
Same row will have the same number of occupied electron shell

# data[].attributes.body
Column(Group)
Row(Period)

# data[].attributes.body
Column = Group
Row = Period

# data[].attributes.body
1)1st shells-maximum 2 electrons
2)2nd and 3rd shell-maximum 8 electrons
3)column-groups(Roman numerals: I,II,III)
>number of outermost electron(valence)
4)rows-period(Arabic numerals: 1,2,3)
>number of occupied electron shells

# data[].attributes.headline
Electron Configuration-Summary of how many electrons are there in each shell

# data[].attributes.subject
Electron Configuration-Summary of how many electrons are there in each shell

# data[].attributes.body
Group 0 is a noble gas(inert=unreactive)
Stable electronic configuration with full electron shells

# data[].attributes.body
-Noble gas(unreactive=inert)
-Stable electronic configuration with full electron shell

# data[].attributes.body
-name doesn’t change if it’s positive ion. Eg. Aluminium atom➡️Aluminium ion. Lithium atom➡️Lithium ion. Magnesium atom➡️Magnesium ion etc.
-name change if it’s negative ion. Eg. Fluorine atom➡️Fluoride ion. Oxygen atom➡️Oxide. Sulfur atom➡️Sulfide etc.[last three letters are -ide]