Periodic Table
Elements
Energy Levels
Periodicity
Groups
100
This tool organizes the known elements and predicts the properties of new ones.
What is the periodic table?
100
The lightest element.
What is hydrogen?
100
The first energy level holds this many electrons.
What are two electrons?
100
When atoms are arranged in order of increasing _____________, there is a periodic repetition of their physical and chemical properties
What is atomic number?
100
Two rows of elements that usually sit under the rest of the periodic table.
What are the lanthanides and actinides?
200
The property used to organize the periodic table.
What is atomic number?
200
This element has an atomic number of 45.
What is rhodium?
200
The third energy level holds this many electrons.
What are eight electrons?
200
This is a physical characteristic the group 1 elements have in common.
What is light weight, metallic, silvery-gray in color?
200
This group of elements starting with "h" reacts strongly with the alkali metals to form salts.
What are the halogens?
300
He put the elements into columns and in rows.
Who was Mendeleev?
300
This element has atomic number 12.
What is magnesium?
300
Beryllium has this many energy levels.
What is "two"?
300
These electrons are on the outermost energy level of an atom.
What are valence electrons?
300
Group of unreactive gases.
What are the noble gases?
400
Word for the columns of the periodic table.
What is a group?
400
The heaviest out of the trio of cobalt, rhodium, and iridium.
What is iridium?
400
What is magnesium?
400
This is a chemical characteristic that changes as group 1 elements increase in atomic number.
What is the strength of the reaction with water?
400
This type of element reacts strongly with water to create hydrogen gas.
What are the alkali metals?
500
The average mass of protons, neutrons, and electrons in all isotopes of an element.
What is the atomic mass?
500
All atoms of an element have the same number of these.
What are protons?
500
What is oxygen?
500
This is a physical characteristic that changes as group 1 elements increase in atomic number.
What is melting/boiling point?
500
This metal is famously unreactive.
What are noble metals such as silver, gold, and platinum?