History of the Atom
Atomic Structure
Charges
Periodic Table
Electron Shells
100
Democritus was the first person to coin the term _______, meaning the smallest unit of matter.
What is atom?
100
Subatomic particles that make up the nucleus of an atom
What are Neutrons and Protons?
100
All protons have a _______________ charge.
What is positive?
100
On a periodic table, the horizontal rows of elements are called __________
What are periods?
100
How many electrons can the 1st energy level of an atom hold?
What are 2 electrons?
200
JJ Thomson made the plum pudding model, which showed that atoms have small particles called _____________.
What are charges?
200
The sum of the protons and neutrons in an atom's nucleus is its _______________.
What is the "atomic mass" or "mass number"?
200
The electric charge of an electron
What is a negative charge?
200
Elements in the same vertical column (group / family) have the same number of _________ _________
What are valence electrons?
200
The greatest number of electrons an atom can hold in its second energy level is ______________
What is 8?
300
What is the name of the atomic model the places the electrons in shells/energy levels?
What is a Bohr Model?
300
____________ particles are negative and don't contribute to the atomic mass because they are so small.
What is electron?
300
The charge of a neutron
What is "no charge" or "neutral"?
300
What to look at on a Periodic Table to determine the number of energy levels an atom has
What are periods?
300
Krypton has _________ energy levels.
What is 4?
400
Chadwick was the scientist who discovered another particle within the atom, called a __________.
What is neutron?
400
The number of __________ determines the atomic number of the element.
What are protons?
400
If an atom has an equal number of protons and electrons, the charge is ______________
What is neutral?
400
About 75% of the elements on the periodic table are...
What are metals?
400
Iodine has _________ valence electrons.
What is 7?
500
Mendeleev organized the elements on the periodic table by their similar _____________.
What are properties?
500
Atoms that have the same number of protons and different numbers of neutrons are called ____________.
What are isotopes?
500
An atom has 15 protons and 18 electrons. Its charge is...
What is -3?
500
On the periodic table there are ____ groups (how many)
What is 18 groups?
500
Draw a Bohr diagram for Chlorine.
