4A1 Periodic Table Flashcards
Explain the arrangement of the periodic table, including groups, periods, and element symbols.
Define:
periodic table
An organized model that includes all discovered elements, providing information about their properties.
Elements are simple substances that cannot be broken down and are composed of identical atoms unique to each element.
Who is known as the ‘Father of the Periodic Table’?
Dmitri Mendeleev
Mendeleev organized known chemical elements by increasing atomic weight and identified patterns in their properties.
Define:
Law of Triads
An organization tool created by Johann Dobereiner that grouped elements with similar properties in sets of three.
An example includes chlorine, bromine, and iodine, which all form salt.
What significant discovery did Henry Moseley make?
He determined that elements should be arranged by increasing atomic number instead of atomic mass.
This led to a more accurate organization of the periodic table.
What are the two main organizational structures of the periodic table?
- Groups (vertical columns)
- Periods (horizontal rows)
Groups show elements with similar properties; periods indicate the number of energy levels in an atom.
How many periods are in the periodic table?
7
Although there appear to be nine rows, the last two are pulled out and belong to the sixth and seventh periods. Sometimes, periods are also referred to as “levels”.
How many groups are in the periodic table?
18
Groups are also referred to as periodic families.
List the three types of elements based on their location in the periodic table.
- Metals
- Nonmetals
- Metalloids
Metals are on the left, nonmetals on the right, and metalloids form a staircase between them.
List three properties of metals.
- Malleable
- Ductile
- Good conductors of heat and electricity
Most elements on the periodic table are metals.
List three properties of nonmetals.
- Brittle in solid form.
- Poor conductors of heat and electricity.
- They form anions in chemical reactions.
Nonmetals are found on the right side of the periodic table.
Define:
metalloids
Elements located along the ‘staircase’ on the periodic table that have properties of both metals and nonmetals.
Examples include boron (B), silicon (Si), germanium (Ge), arsenic (Ar), antimony (Sb), tellurium (Te), and astatine (At).
List three properties of metalloids.
- Solids at room temperature.
- Moderate conductors of electricity and heat.
- Brittle in solid form.
Metalloids tend to have chemical properties that are more similar to nonmetals than metals.
What are valence electrons?
Electrons in the outermost energy orbital of an atom.
The number of valence electrons increases across a period and is the same within a group.
What is the general pattern for determining valence electrons in elements?
Final digit of the group number indicates valence electrons.
This applies except for transition metals and helium.
True or False:
Elements in the same group have the same number of valence electrons.
True
This is true for most elements, excluding transition metals and helium.
For example, all elements in Group 3 have 3 valence electrons.
How many valence electrons do elements in group 1 have?
1
Each element in group 1 only has 1 valence electron, which determines how it bonds and interacts with other elements.
What role do valence electrons play in chemical bonding?
They interact with other atoms to form chemical bonds.
Valence electrons can be shared or donated during bonding.
Where are transition metals located on the periodic table?
Groups 3-12, including lanthanides and actinides.
Their valence electrons can be found in d or f orbitals.
What is the lightest element in the periodic table?
Hydrogen
(H)
Hydrogen has an atomic number of 1 and an atomic mass of approximately 1 amu.
What are the “BIG 6” elements commonly found in living organisms?
- Carbon (C)
- Hydrogen (H)
- Nitrogen (N)
- Oxygen (O)
- Phosphorus (P)
- Sulfur (S)
These elements form the molecules critical for biological systems, such as proteins and nucleic acids.
Why are alkali metals highly reactive?
They have 1 valence electron, which they readily lose to form positive ions (cations).
Alkali metals are found in group 1 of the periodic table.
Examples include lithium (Li) and sodium (Na).
Which element has the symbol K?
Potassium
Potassium is an alkali metal with an atomic number of 19.
What is the symbol, atomic number, and mass of sodium?
- Symbol: Na
- Atomic number: 11
- Mass: Approximately 23
Sodium is an alkali metal and highly reactive.
What are the characteristics of alkaline earth metals?
- They are elements in group 2.
- They have 2 valence electrons.
- They are less reactive than alkali metals but still form basic oxides.
Examples include beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).
Fill in the blank:
The elements in Group 17 are called ________.
halogens
Halogens are highly reactive nonmetals that commonly form salts with metals.
List three examples of halogens.
- Fluorine (F)
- Chlorine (Cl)
- Bromine (Br)
Other examples include iodine (I) and astatine (At).
Fluorine is the most reactive halogen and a strong oxidizing agent.
Which group has elements that exist as diatomic molecules?
Group 17 (Halogens)
Examples: F₂, Cl₂, and Br₂.
What are elements in Group 18 called?
Noble gases
They are inert due to having a full outer energy level of electrons.
List three examples of noble gases.
Helium (He), Argon (Ar), Krypton (Kr).
Other examples include xenon (Xe) and radon (Rn).
What is the symbol, atomic number, and mass of helium?
- Symbol: He
- Atomic number: 2
- Mass: Approximately 4
Helium is a noble gas used in balloons and cooling systems.
How many energy levels are there in total?
7
These levels correspond to the periods on the periodic table.
Fill in the blank:
The d orbitals have an energy level that is _____ than the period number.
1 less
This is important for understanding transition metals.
Fill in the blank:
The f orbitals have an energy level that is _____ than the period number.
2 less
This adjustment is necessary for elements in the lanthanide and actinide series.
Fill in the blank:
Elements in the d-block are called ______ metals.
transition
These include elements like copper (Cu) and zinc (Zn).
What is the element with the atomic number 26?
Iron
(Fe)
Iron is a transition metal critical for steel production.
What are the lanthanides and actinides?
They are f-block elements found in the sixth and seventh periods.
They are often referred to as rare earth metals.
Lanthanides include elements 57-71, and actinides include elements 89-103.
Why are the lanthanides and actinides separated from the main table?
To make the table more compact and readable.
They are part of the f-block and do not fit well into the main group/period layout.
Fill in the blanks:
Carbon (C) is a ______ with an atomic number of ______.
nonmetal; 6
Carbon is crucial for organic chemistry and life.
What is the symbol, atomic number, and mass of oxygen?
- Symbol: O
- Atomic number: 8
- Mass: Approximately 16
Oxygen is a nonmetal and is crucial for respiration and combustion.
What is the element symbol for gold?
Au
Gold has an atomic number of 79 and an atomic mass of approximately 197 amu.
