Periodic tables Flashcards
What did Bohr propose about electron movement in his atomic model?
Electrons revolve around the nucleus in fixed orbits.
What happens when electrons jump between energy levels in Bohr’s model?
Electrons can absorb or emit energy.
What are the designations for energy levels in Bohr’s model?
K, L, M, N…
What is the maximum number of electrons in the K energy level?
2 electrons.
What is the maximum number of electrons in the L energy level?
8 electrons.
What does the Quantum Mechanical Model replace?
Fixed orbits with electron clouds (orbitals).
What are the types of orbitals in the Quantum Mechanical Model?
- s (sharp)
- p (principal)
- d (diffuse)
- f (fundamental)
How many electrons can an s orbital hold?
2 electrons.
How many electrons can a p orbital hold?
6 electrons.
How many electrons can a d orbital hold?
10 electrons.
How many electrons can an f orbital hold?
14 electrons.
What is the Aufbau Principle?
Electrons fill the lowest energy orbitals first.
What does the Pauli Exclusion Principle state?
An orbital can hold a maximum of two electrons with opposite spins.
What is Hund’s Rule?
Electrons fill degenerate orbitals singly before pairing.
Fill in the blank: The electron configuration of Oxygen is _______.
1s² 2s² 2p⁴
What were Dobereiner’s Triads?
Grouped elements into sets of three with the middle element averaging properties.
What was Newlands’ Law of Octaves?
Arranged elements by increasing atomic mass with every 8th element having similar properties.
What is Mendeleev’s Periodic Law?
The properties of elements are periodic functions of their atomic masses.
How did Mendeleev arrange elements in his periodic table?
By increasing atomic mass in groups (columns) and periods (rows).
What significant prediction did Mendeleev make?
Left gaps for undiscovered elements like gallium and germanium.
What is Moseley’s Modern Periodic Law?
Properties of elements are periodic functions of their atomic number (Z).
How are elements organized in the modern periodic table?
- Groups (1-18)
- Periods (1-7)
- Blocks (s, p, d, f)
What advantage does the modern periodic table have over Mendeleev’s table?
Fixed placement anomalies and corrected atomic mass inconsistencies.
What trend occurs in atomic size across a period?
Decreases due to increasing nuclear charge.
