Groups
What is a group?
A vertical column on the periodic table
What do elements in a group have in common?
(Two things)
Same number of valence electrons and same chemical properties
Why is hydrogen considered to be in a class of its own?
Because it only has 1 proton, 1 electron, and no neutrons
What was the first periodic table organized by?
Atomic mass
What is a trend?
A particular change in a particular direction
What are group 1 elements called? Name one of their properties.
Alkali metals
React explosively with water
Never found as pure elements in nature
Soft and shiny
What is a period?
A horizontal row on the periodic table
What are characteristics of all metals?
Shiny, conduct heat and electricity well
What is the modern periodic table organized by?
Atomic number
Based on the trends for electronegativity, which of the following elements has the lowest electronegativity?
Barium (Ba), Germanium (Ge), Oxygen (O), Scandium (Sc),
Barium (Ba)
What are group 2 elements called? Name one of their properties.
Alkaline Earth Metals
React explosively with water
Present in minerals and sediments
Can occur as pure elements in nature
Harder than alkali metals
What do elements in a period have in common?
Same number of orbitals/energy levels
What are characteristics of nonmetals?
Do not conduct heat and electricity well
Who organized the first periodic table?
Dmitri Mendeleev
Based on the trends for atomic size, which atom has the smallest atomic size?
Barium (Ba), Germanium (Ge), Oxygen (O), Scandium (Sc),
Oxygen (O)
What are group 17 elements called? Name one of their properties.
Halogens
React with metals to form salts
Can occur as solids, liquids, or gases
Most are diatomic
Why are elements in groups 3-12 called Transition Metals?
Because their electron configurations/valence electrons are not regular, stable, or predictable
Why are some elements called metalloids or semimetals?
Because they have properties that are between metals and nonmetals
They are weak conductors of heat and electricity
Who created the modern periodic table?
Henry Moseley
Based on the trends for ionization energy, which of the following elements has the highest ionization energy?
Magnesium (Mg), Fluorine (F), Phosphorus (P), Chlorine (Cl),
Fluorine (F)
What are group 18 elements called? Name one of their properties.
Noble gases
Unreactive
All gases
Why are elements in Group 7 called Actinides? What property do they all have in common?
Because they follow the element actinium
They are all radioactive
Which side of the periodic table has metals and which side of the periodic table has nonmetals?
(Choose Left or Right)
Left - Metals
Right - Nonmetals
What is periodic law?
States that when elements are organized by their atomic numbers, then similar groups of elements with similar properties show up periodically
Based on the trends for ionic size, which of the following elements has the largest ions?
Magnesium (Mg), Fluorine (F), Phosphorus (P), Chlorine (Cl),
Phosphorus (P)