Atomic Structure
What is an atom?
They are the smallest units of an element that still retain the properties of the element
What did Democritus believe/teach?
There was a limit to how many times a substance could be divided. Atomos.
What is the periodic table?
The organization of elements in order of atomic numbers.
What are valence electrons?
Electrons in the outermost ring of an electron shell.
What is an ion?
An atom or group of atoms that gains or losses an electron. 300
What are the three subatomic particles that make up an atom? What is the location for each?
dj neutron, proton - nucleus
electron - outside/around nucleus
What did John Dalton theorize?
Every element is made up of atoms, atoms cannot be subdivided, atoms of the same element are identical and atoms of different elements can join to form molecules.
What are the rows in a periodic table called?
How many electrons fill up the first and second ring on the electron shells?
first - 2
second - 8
both - 10
What is ionization?
The process of adding or removing electrons from an atom or group of atoms
What are the charges for the subatomic particles?
neutron - neutral
electron - negative
What model did JJ Thompson create? What did it entail?
JJ Thompson, discovered electrons in 1897 and in 1904 created the Plum Pudding Model
Plum Pudding Model: the electrons were embedded in a uniform sphere of jelly like positive charge, the electrons were thought to be mobile
What are the columns in the Periodic table called?
Groups
What is an isotope?
dj Atoms of an element that have a different number of neutrons.
What happens to the charge of an atom?
The charge of the atom will change during ionization, becoming either positive or negative.
What does the atomic number determine?
Location of element on the periodic table and the number protons/electrons
What experiment did Rutherford perform and what were the conclusions?
Ernest Rutherford conducted the Gold Foil experiment - a thin sheet of gold foil was bombarded with alpha particles, it was discovered that while most of the particles were deflected, a small percentage bounced off the foil
It was concluded that atoms were mostly empty space
The nuclear model was created
Protons and neutrons in the nucleus at the center of the atom
Electrons are distributed around the nucleus
The elements have similar physical properties when they are in the same period
What three things could occur during a chemical reaction?
t Electron removal, sharing or addition
What is a cation?
dj An ion with a positive charge, it has lost electrons
What does the atomic mass tell you?
The average of all isotopes of an element
What model did Neil Bohn create and what did it explain?
Neil Bohr developed Bohr’s Model
Electrons move in an orbit around the nucleus (like the planets orbit the sun)
The path defines the energy levels of the electron
An electron can gain or lose energy by moving up or down a level
The elements in the same group react with other elements in similar ways
How many electrons can fill up the third shell?
18
An ion with a negative charge, it has gained electrons