Atom Basics
What is the smallest unit of matter that retains the properties of an element?
Answer: An atom
Which subatomic particle has a positive charge?
Proton
Who proposed the planetary model of the atom?
Niels Bohr
Which direction on the periodic table does atomic size increase?
Down and to the left
Who first used the term 'atomos' meaning 'uncuttable'?
Democritus
Which subatomic particle has a negative charge?
Electron
Which scientist discovered the nucleus using gold foil?
Ernest Rutherford
Which trend increases as you move left to right across a period?
Electronegativity
What part of the atom contains nearly all its mass?
The nucleus
What particle has no charge but mass nearly equal to a proton?
Neutron
Who discovered the electron?
J.J. Thomson
What is the energy required to remove an electron called?
Ionization energy
What is the number of protons in an atom called?
Atomic number
Where are electrons found in an atom?
In energy levels or electron shells
What model replaced Bohr’s, using orbitals instead of orbits?
Quantum Mechanical Model
Which element has the highest electronegativity?
Fluorine