Periodic Trends
This trend decreases across a period and increases down a group.
Atomic Radius
This family is known for being highly reactive metals in Group 1.
Alkali metals
What are the horizontal rows called on the periodic table?
Periods
He is credited with creating the first periodic table
Dmitri Mendeleev
I am a noble gas with atomic number 10, often used in bright advertising signs.
Neon
Energy required to remove an electron from an atom is called...
Ionization energy
These elements in Group 17 form salts with metals.
Halogens
The periodic table is arranged by increasing what?
Atomic number
Mendeleev arranged elements by which property?
Atomic mass
I am a gas that helps keep balloons floating.
Helium (He)
Between Na (sodium) and Cl (chlorine), which has the larger atomic radius?
Sodium (Na)
This family contains elements that are good conductors
Metals
The number of ____ determines an elements atomic number
This scientist later rearranged the table by atomic number.
Henry Moseley
I am the main gas we breathe in the air, making up about 78% of Earth’s atmosphere.
Nitrogen (N)
Between F (fluorine) and Br (bromine), which has the higher electronegativity?
Fluorine (F)
These elements have properties of both metals and nonmetals.
Metalloids
Vertical columns on the periodic table are called...
Groups or families
The modern periodic table is arranged by which law?
I am the most reactive metal found in Group 1.
Francium
Among O (oxygen), Se (selenium), and S (sulfur), which has the lowest electronegativity?
Selenium (Se)
This group of elements is unreactive due to a full valence shell.
Noble gases
Elements in the same group share what common characteristic?
Valence electrons
What major change did Henry Moseley make to the periodic table?
He arranged elements by atomic number instead of atomic mass
What element is the only liquid metal at room temperature?
Mercury