Atomic Scientists & Their Contributions
This ancient Greek philosopher suggested that matter is made of tiny, indivisible particles called “atomos.”
Who is Democritus?
The positively charged particle found in the nucleus.
What is a proton?
Atomic number
What is the number of protons?
K-shell
What is the first energy level holding up to 2 electrons?
Loss of electrons
What is forming a cation?
This scientist proposed that atoms are solid spheres
Who is John Dalton?
Electron cloud
What is the region where electrons are likely to be found?
Isotopes
What are atoms of the same element with different numbers of neutrons? What is 8?
M-shell
What is the third energy level holding up to 18 electrons?
This term describes how electrons are distributed across shells.
What is electronic configuration?
Plum pudding model
Who is J.J. Thomson?
The total number of protons and neutrons in the nucleus.
What is mass number?
Carbon-14 The maximum number of electrons in the M shell.
What is the isotope used in radiocarbon dating?
L-shell
What is the second energy level holding up to 8 electrons?
Electrons found in this outermost shell determine an element’s chemical reactivity.
What are valence electrons?
This scientist’s experiment proved that atoms have a small, dense, positively charged nucleus.
Who is Ernest Rutherford?
Atoms of the same element with different numbers of neutrons.
What are isotopes?
Ion formation
What is the process when atoms gain or lose electrons?
Octet rule
What is the rule that atoms tend to have 8 electrons in their outer shell?
This rule calculates the maximum number of electrons a shell can hold.
What is the 2n² rule?
He suggested that electrons travel in fixed orbits or energy levels around the nucleus.
Who is Niels Bohr?
Neutron
What is the neutral particle that contributes to mass?
Gain of electrons
What is forming an anion?
Electron configuration of sodium
What is 2, 8, 1?
Electron configuration of Na⁺
What is 2, 8?