Atoms Flashcards
What is strong nuclear force?
Holds protons and neutrons in a nucleus together
Explain alpha decay
Two protons and two neutrons are emitted. The atomic number reduces by two and mass number reduces by 4. Elements change since atomic number is changing
Beta decay
Converts neutron to proton by weak nuclear force. Atomic number increases, mass number stays the same
Beta positive decay (positron emission)
Proton converted to neutron. Atomic number is one less and mass number remains the same
Electron capture
Electron captured from she’ll and used to convert a proton to a neutron. Atomic number reduced and mass number stays the same
Gamma decay
Expulsion of energy after coming down from an excited state. No mass or atomic number change. Emits photon
What is half life?
Time it takes half substance to decay
What is limit to the Bohr model?
Cannot predict atomic spectra of many electron atoms, which is why quantum model was made
What are the four numbers for the quantum model?
Shell, subshell, orbital, and spin
What electrons have greater energy?
Those farthest outside
Three rules of electron configurations
Electrons occupy the lowest orbital possible, electrons in same subshell occupy orbitals singly (one spin up), no more than two electrons in any given orbital
Aufbau Principle
Electrons occupy lowest orbital possible first
Hunds rule
Electrons occupy subshell singly
Pauli exclusion principle
No more than two electrons in a given orbital
What does diamagnetic mean?
Atom has all electrons spin paired. There is an even number of electrons. There is no net magnetic field since spins cancel each other. Will be repelled by and external magnetic field
