3 Particles:

• 1. PROTON (p+) → POSITIVE charged particle, found in the NUCLEUS, that makes up at least HALF of the MASS of an atom!

• The number of p+ determines the TYPE of atom (they DON’T change)!

• 2. NEUTRON (n0) → NEUTRAL particle, found in the NUCLEUS, that makes up the rest of the mass of an atom.

• The number of n0 can CHANGE → ISOTOPE

• Act as the “glue” to keep the protons together (Nuclear force)

3 Particles

• 3. ELECTRON (e-) → NEGATIVE particle, found in the CLOUD, that has almost NO mass.

• The number of e- can CHANGE → makes charged atoms (IONS)

• Electrons exist in ENERGY LEVELS, have energy, and are responsible for CONNECTING atoms together (BOND)

I. What are the parts of the current (modern) model used today?

• 2 PARTS:

• NUCLEUS: the dense/solid CENTER part of an atom where most MASS is found.

• Contains PROTONS and NEUTRONS

I. What are the parts of the current (modern) model used today?

• ELECTRON CLOUD:  mostly empty space surrounding the nucleus, where electrons are found.

• Broken in to ENERGY LEVELS:  The DISTANCE an electron is away from the nucleus (specific ORBITALS can be found within each energy level).

• Electrons can change energy levels (gain energy=moving up; lose energy=down)

Bohrs Model

Electrons orbit the nucleus in orbits that have a set size and energy.

2. The lower the energy of the electron, the lower the orbit.

3. This means that as electrons fill up the orbitals, they will fill the lower energy level first.

4. If that energy level is fill (or at capacity), a new energy level will begin.

5. Radiation is when an electron moves from one level to another.

Atomic Emission Spectrum

is the pattern of lines formed when light passes through a prism to separate it into the different frequencies of light it contains.

What do you think is happening in this image?

Atomic Emission Spectra

Ground state of an atom is the lowest energy state of the atom. When those atoms are given energy, the electrons absorb the energy and move to a higher energy level.

Atomic Emisions Spectra

Excited state of an atom is a state where its potential energy is higher than the ground state.

An atom in the excited state is not stable. When it returns back to the ground state, it releases the energy that it had previously gained in the form of electromagnetic radiation