History of the Atom
Who showed electrons in specific energy levels
Bohr
What is another name for Groups
Families
The Atomic number will always represent the number of ____
Protons
Who was the first person to use the term atom
Democritus
Give 2 examples of an alkali metal
Lithium, sodium, potassium, rubidium, cesium, francium
The cathode Ray experiment led to what particle being discovered?
Electron
Vertical columns 1-18 are called what
Groups or families
In a neutral atom, how do you find the number of electrons
They will equal the number of protons.
Which scientist used the cathode ray tube to discover electrons
JJ Thomson
What groups represent the Transition Metals
Groups 3-12
The alpha (+) particles in Rutherford's were used to
bombard sheets of gold
Horizontal rows 1-7 are called what
Periods
How do you figure the number of Neutrons in an atom
Subtract the Protons from the rounded atomic mass
Which scientist's ideas form the Atomic Theory of Matter
John Dalton
Give 3 examples of a Halogen
Fluorine, chlorine, bromine, iodine, astatine
True or False:
Rutherford and Bohr modeled their experiments and their theories after Dalton.
True
Group 1 is called
Alkali Metals
How many electrons does Uranium have
92
Which scientist proposed a model of the atom that is similar to a model of our solar system
Niels Bohr
What is the name & number of the group of elements that do not react
Group 18 the Noble gases
True or False:
The electron was discovered by Chadwick in 1886
False it was discovered by JJ Tompson
What group are the Halogens in
Group 17
Protons + Neutrons = __________
Mass number
Which scientist said every electron was a certain distance from the nucleus in a specific energy level
Niels Bohr
Why is the nucleus positive
Because it is made up of protons & neutrons. The protons are positive and the neutrons have no charge....thereby making the nucleus positive