C2 - The Periodic Table Flashcards
What is the periodic table?
A list of elements arranged according to their atomic number
What do elements in the same group of the periodic table have in common?
The same number of electrons in their outer shell and similar properties
Which group of elements is known for being very unreactive gases?
The noble gases
What determines an element’s chemical properties?
The number of electrons in its outer shell
List three general physical properties of metals.
- Lustrous (shiny)
- Good conductor
- Malleable and ductile
List three general physical properties of non-metals.
- Dull
- Poor conductor
- Brittle
Where are metals located on the periodic table?
On the left side
Where are non-metals located on the periodic table?
On the right side
What type of ions do metals form?
Positive ions
What type of ions do non-metals form?
Negative ions
What does the group number in the periodic table indicate?
How many electrons are in the element’s outer shell
What does the period number in the periodic table indicate?
How many shells of electrons an element has
Who proposed an early version of the periodic table based on atomic weight?
Mendeleev and Newlands
What was Newlands’ Law of Octaves?
Every 8th element had similar properties
What criticism did Newlands face regarding his periodic table?
He grouped elements with very different properties
What was a significant change in the arrangement of the modern periodic table?
It is arranged by atomic number instead of atomic weight
How did the discovery of isotopes impact the periodic table?
It explained why ordering elements by atomic weight was not always correct
True or False: All elements in the same group have the same number of protons.
False
Fill in the blank: The elements with atomic numbers 58 - 71 are called the _______.
Lanthanides
Fill in the blank: The elements with atomic numbers 90 - 103 are called the _______.
Actinides
What was one of the key contributions of Mendeleev to the periodic table?
He left gaps for undiscovered elements
Which two scientists are credited with early periodic table proposals?
Mendeleev and Newlands
List two properties of metals.
- High melting point
- Strong
List two properties of non-metals.
- Low melting point
- Low density
What are Group 7 elements commonly known as?
Halogens
Halogens include fluorine, chlorine, bromine, and others.
How many electrons are in the outer shell of Group 7 elements?
Seven
This configuration influences their chemical behavior.
What type of molecules do halogens exist as?
Diatomic molecules
Examples include F2, Cl2, Br2.
What happens when a more reactive halogen is introduced to a compound?
It can displace another halogen
Example: potassium bromide + chlorine → potassium chloride + bromine.
What trend occurs in the density, boiling point, and melting point of halogens as you move down the group?
They increase
Reactivity decreases down the group.
What are Group 0 elements also known as?
Noble Gases
These include helium, neon, argon, and others.
Why are noble gases considered unreactive?
They have a complete outer shell of electrons
This stability prevents them from reacting easily.
What happens to the boiling points of noble gases as you move down the group?
They increase
This trend is consistent across the group.
What are Group 1 metals commonly referred to as?
Alkali Metals
They produce alkaline solutions when reacting with water.
What is the characteristic of Group 1 elements related to their outer shell?
They have a single electron
This leads them to lose an electron to achieve stability.
What trend occurs in the density and reactivity of Group 1 metals as you move down the group?
They increase
Melting point decreases down the group.
What do Group 1 elements react vigorously with to form chlorides?
Chlorine
Example: sodium + chlorine → sodium chloride.
What do Group 1 metals form when they react with oxygen?
Metal oxides
Example: potassium + oxygen → potassium oxide.
What do Group 1 metals produce when they react with water?
Metal hydroxide and hydrogen
Example: sodium + water → sodium hydroxide + hydrogen.
Where are transition metals located in the periodic table?
Central section
Includes elements like chromium (Cr), cobalt (Co), and iron (Fe).
How do transition metals generally compare to Group 1 metals in terms of physical properties?
Harder, stronger, denser, higher melting points
Transition metals are typically more robust.
Are transition metals more or less reactive than Group 1 metals?
Less reactive
Some transition metals do not react with oxygen or water at all.
What role do transition metals commonly serve in chemical processes?
Catalysts
They facilitate reactions without being consumed.
What is the relationship between reactivity and the ability to lose or gain electrons?
More easily an electron is lost or gained, the more reactive the element
This principle applies to both metals and non-metals.
How does the reactivity of Group 1 elements change as you move down the group?
Increases
This is due to larger atomic size and weaker attraction to the nucleus.
How does the reactivity of Group 7 elements change as you move down the group?
Decreases
Larger atomic size makes it harder to gain an electron.
What is an example of an element that can form ions with different charges?
Iron
It can form Fe²⁺ and Fe³⁺ ions.
