Waves, periodic table, and energy levels Flashcards
Element
An element is a pure substance made of only one type of atom.
How many elements are there?
There are a limited number of elements (118)
All substances are made up of either:
- A single element
2. A combination of elements (compounds)
How can you determine an element?
The number of protons
Periodic table
The periodic table is a way of organizing the elements so that the repeating properties of the elements line up.
What are the parts on the periodic table?
- Atomic number
- Element symbol
- Element name
- Average atomic mass
Atomic number
Number of protons or electrons if an atom is neutral.
Neutral atoms:
- Have an equal number of protons and electrons
2. The atomic number is the number of the total electrons in that atom
How many protons does the element Tc have?
43
Wave
a wave is a disturbance that travels through space carrying energy.
Frequency
The number of waves per second (measured in Hertz-Hz)
Wavelength
The distance between each repeating wave (meters- m)
- Peak to peak
- Trough to trough
Amplitude
The height of a wave going from middle to top, (measured in meters-m)
Wave speed
Wave speed is how fast the wave moves away from it’s source (m/s-meters per second)
Parts of a wave
- Frequency
- Amplitude
- Wavelength
- Wave speed
Wave equation
v=f*lambda
v= Wave speed (m/s)
f=Frequency (Hz)
lambda= wavelength (m)
What is another equation that can be used to find wave speed?
v=d/t
Electrons have lower potential energy when:
they are closer to the nucleus, reaching a more stable state.
Energy and electrons
- Electrons can only have particular energies in atoms, called energy levels.
- Electrons cannot have energies between levels
Each energy level…
only holds a certain number of electrons
What energy level do electrons fill first?
The lowest energy level. When it is full, the electrons start filling the next lowest energy level.
What are the lowest and second-lowest energy levels called?
First and second energy level
How many electrons can each energy level hold?
First energy level= max 2 electrons
Second energy level= max 8 electrons
Number of energy levels for an atom:
The number of energy levels an atom has electrons in is the same row that element is in on the periodic table.
Outermost energy level:
The highest energy level an atom has electrons in is called the outermost energy level. The number of electrons in the outermost energy level is the same as the number of main group elements in the last row of the periodic table.
