abeka phy sci 9 section 13.2

quiz on thursday i think- jkjk it’s tmr (3/8)

nucleus

where protons and neutrons are found

protons

 positive charge

atomic number

number of protons in the nucleus

neutrons

atoms with no charge

isotopes

atoms of the same element that have different number of **neutrons**

quarks

smaller particles of protons and neutrons

electrons

negative charge 

electron shell

layers that surround the nucleus

ion

an atom that has electric charge

anion

negative charge ion

cation

 positive charge ion

mass number

total number of protons and neutrons 

atomic mass unit

measures atom’s mass

average atomic mass

average mass of isotopes

quantum theory

tiny particles do not absorb or release energy in a smooth flow

bohr model

 shows electrons surrounding nucleus in circles

wave-mechanical model

shows electron wave around nucleus

heisenberg uncertainty principle

 it's impossible to know both the position and velocity of an electron at the same time

electron-cloud model

electron as dots surrounding the nucleus

orbitals

 electrons move unpredictability through regions of space

quantum (4) numbers

 represents overall motion of each electron

pauli exclusion principle

no two electrons in an atom can have the same four quantum numbers