atoms Flashcards
(12 cards)
What are the three subatomic particles of atoms?
- Protons
- Neutrons
- Electrons
Protons have a positive charge, neutrons have a neutral charge, and electrons have a negative charge.
Where is the nucleus located in an atom?
In the middle of the atom, containing protons and neutrons.
The nucleus is surrounded by an electron cloud.
What is the atomic number of an element?
The number of protons in the nucleus of the atom.
Each element has a unique atomic number that identifies it.
What is the mass number of an element?
The total number of protons and neutrons in the nucleus of the atom.
Protons and neutrons have approximately the same mass.
What is the maximum number of electrons in the K shell?
2
The K shell is the first electron shell closest to the nucleus.
What is the maximum number of electrons in the L shell?
8
The L shell is the second electron shell.
What is the maximum number of electrons in the M shell?
18
However, for the first 20 elements, the M shell will only have 8 electrons.
What is the maximum number of electrons in the N shell?
32
The N shell is the fourth electron shell.
What is the ground state of an atom?
The state where electrons are at the lowest energy level and most stable.
Electrons fill the lowest energy shells first.
What happens when electrons absorb energy?
Electrons move to an excited state.
When they return to the ground state, they can emit colored light.
What is electron configuration?
The arrangement of electrons in the shells of an atom.
Shells are filled starting with the K shell.
Fill in the blank: The outer shell for the first 20 elements never has more than _______ electrons.
8
The 3rd shell will only fit 8 electrons instead of 18.
