Atomic Structure & Nucleus Flashcards
4E p15
What occupies most of the atoms volume?
Electrons
what subatomic particle has the most mass?
Neutrons
protons
electrons
What is atomic number?
It is the number of protons and electrons
p=e
How to find the number of neutrons?
Mass no - atomic no
What are isotopes?
Atoms with the same number of Protons but different number of neutrons
They have the same atomic number(small) but different mass number(big)
How are isotopes written?
Symbol and mass number at the top
What are ions?
Atoms become ions after gaining or losing an electron
cations
are positive
Loss of electron happened
anions
are negative
gain of e happened
Where do we put the electrons for cation and anion equations?
cation: put in products (Na = Na + e)
anion: put in reactants (O +2e = O)
How to find the atomic mass of an isotope?
Sum of (% of isotope x mass of isotope)
how are isotopes of atoms determined?
mass spectrometer (IADD)
Ionization (sample is already)
acceleration (through electromagnet)
deflection (circular path)
detection (on plate)
What does Dalton’s hypothesis for constant mass explain?
Naturally a green samples of an element have almost the same mixture of isotopes
how are artificial elements different from natural element in terms of atomic mass and atomic number?
Artificial elements have atomic number greater than 92 & don’t have an atomic mass
what is the value of the fundamental unit of charge
1.6 x 10^-19 C
What subatomic particle uniquely identifies an element?
Proton
what is the energy level of the electrons that are closer to the nucleus?
They are at lower energy level
Name the 3 isotopes of Hydrogen.
Atomic mass 1 amu = protium
2 amu = deuterium
3 amu = tritium
atomic weight
Weighted average of different isotopes
number on the periodic table
Corresponds with mass number
What is a mole and what is it equals to?
Atoms, ions, molecules
6.02 x 10^23