The Particle Theory of Matter
- Matter is made of particles that are in constant motion
- Every kind of matter is made of one or more elements
- Atoms are the smallest particle of an element
Elements
- Elements are the building blocks of all matter
- The periodic table is a list of all of the elements that can build matter
Atomic Mass Unit (AMU)
- This is the protons, neutrons, and electrons of the atoms of that element
- The mass of the proton and neutron are about the same, but the mass of the electron is much smaller (about 1/2000 the mass of the proton or neutron) – so the majority of the atomic mass is contributed by the protons and neutrons
Proton
- Positively charged atomic particle ( + )
- Located in the nucleus of the atom
- The number of protons in an atom’s nucleus is also the atomic number
- The weight of 1 proton is 1 AMU
Neutron
- Neutrally charged atomic particle (no charge)
- Located in the nucleus of the atom
- The weight of one neutron is 1 AMU
- For the atoms of the first 20 elements, the number of neutrons is either equal to or slightly greater than the number of protons
Electron
- Negatively charged atomic particle ( - )
- Located outside the nucleus of the atom in energy levels or energy shells
- The number of electrons surrounding an atom’s nucleus is generally equal to the number of protons
- Have almost no weight (1/1836 the size of a proton) – so electrons are not counted when weighing an atom
Atomic Structure:
1. Nucleus: The center of the atom that contains the mass of the atomb
2. Electron cloud: Region that surrounds the nucleus that contains most of the space in the atom
What's in the Nucleus?
Protons: positively charged subatomic particles
Neutrons: neutrally charged subatomic particles
What's in the Electron Cloud?
Electron: the subatomic particle with a negative charge and relatively no mass
Do Subatomic Particles Balance Each Other?
number of protons = number of electrons
Bohr Model
The Bohr Model shows all of the particles in the atom.
- Matter is made of particles that are in constant motion
- Every kind of matter is made of one or more elements
- Atoms are the smallest particle of an element
Elements
- Elements are the building blocks of all matter
- The periodic table is a list of all of the elements that can build matter
Atomic Mass Unit (AMU)
- This is the protons, neutrons, and electrons of the atoms of that element
- The mass of the proton and neutron are about the same, but the mass of the electron is much smaller (about 1/2000 the mass of the proton or neutron) – so the majority of the atomic mass is contributed by the protons and neutrons
Proton
- Positively charged atomic particle ( + )
- Located in the nucleus of the atom
- The number of protons in an atom’s nucleus is also the atomic number
- The weight of 1 proton is 1 AMU
Neutron
- Neutrally charged atomic particle (no charge)
- Located in the nucleus of the atom
- The weight of one neutron is 1 AMU
- For the atoms of the first 20 elements, the number of neutrons is either equal to or slightly greater than the number of protons
Electron
- Negatively charged atomic particle ( - )
- Located outside the nucleus of the atom in energy levels or energy shells
- The number of electrons surrounding an atom’s nucleus is generally equal to the number of protons
- Have almost no weight (1/1836 the size of a proton) – so electrons are not counted when weighing an atom
Atomic Structure:
1. Nucleus: The center of the atom that contains the mass of the atomb
2. Electron cloud: Region that surrounds the nucleus that contains most of the space in the atom
What's in the Nucleus?
Protons: positively charged subatomic particles
Neutrons: neutrally charged subatomic particles
What's in the Electron Cloud?
Electron: the subatomic particle with a negative charge and relatively no mass
Do Subatomic Particles Balance Each Other?
number of protons = number of electrons
Bohr Model
The Bohr Model shows all of the particles in the atom.