Origin of the Atom 1
What was John Dalton's major contribution to Atomic Theory?
Elements are made up of atoms, and atoms of different elements look different
What country did most of the scientists who worked on Atomic Theory do their work?
England
How many Valence Electrons does Sulfur (S) have?
6 Valence Electrons
The Columns in the Periodic Table are called:
Families
What is an Ion?
An atom that has a positive or negative charge
What was Niels Bohr's major contribution to Atomic Theory?
The electrons (negative particles) orbit around in different layers called "shells"
What did Thomson originally call the negative sub-atomic particles?
Corpuscles
The first Energy Shell of every atom holds a maximum of _____ electrons?
2 electrons
The Rows in the Periodic Table are called:
Periods
The Periods on the Periodic Table all have the same:
Number of Energy Shells
What was Democritus' major contribution to Atomic Theory?
Everything in the universe is made up of a small "uncuttable" he called Atomos
Why did Democritus have a hard time convincing the public of his "Atomos" theory?
The public believed the more famous philosophers Aristotle and Plato, who taught that everything was made up of the 4 elements
How do I find the number of Protons in an atom based on the Periodic Table?
The Atomic Number
According to the Octet Rule, how many Valence Electrons are all atoms trying to obtain?
8 Valence Electrons
The Families on the Periodic Table all have the same:
What was JJ Thomson's major contribution to Atomic Theory?
There is something smaller than atoms; positive and negative particles
Explain Thomson's Plum Pudding Model
Thomson thought that the atom was like plum pudding; a positive "cake" with chunks of negative "plums" floating around inside
How do I find the number of Electrons in an atom based on the Periodic Table?
The Atomic Number
Which column on the Periodic Table contains the most reactive elements?
The 1st column (called the Alkali Metals)
What is a Covalent Bond?
A chemical bond where two atoms share Valence Electrons
What was Ernest Rutherford's major contribution to Atomic Theory?
The atom is mostly empty space; positive particles are in the small center, while the negative particles orbit around
Explain Rutherford's Gold Foil Experiment
Rutherford fired Alpha Particles (positively charged) at a piece of Gold Foil. Most of the particles went through, while a few reflected and refracted. This showed that atoms are mostly empty space
How do I find the number of Neutrons in an atom based on the Periodic Table?
Atomic Mass minus Atomic Number
Which family is the LEAST reactive family?
The Noble Gases (they already have 8 Valence Electrons)
What is an Ionic Bond?
A chemical bond where one Valence Electron is given to another atom, making them both ions