The Periodic Table Flashcards
What does the modern Periodic Table list?
Approximately 100 elements
What was a key feature of the first lists of elements?
Ordered by atomic mass with no gaps
How did Mendeleev’s Periodic Table differ from the modern one?
Elements were not grouped appropriately and had no clear distinction
What discovery allowed scientists to group elements by similar chemical properties?
The discovery of electrons
How are elements ordered in the modern Periodic Table?
By atomic number
What did the discovery of neutrons lead to?
The discovery of isotopes
What problem did isotopes explain in the Periodic Table?
Why some elements didn’t fit when organized by atomic mass
What significant prediction did Mendeleev make?
Properties of undiscovered elements based on gaps in his table
What are the elements in Group 0 called?
Noble gases
What are the properties of noble gases?
- Full outer shells with eight electrons
- Very unreactive (inert)
- Do not bond to form molecules
What is the primary grouping of elements in the Periodic Table?
By chemical properties
Fill in the blank: The elements in Group 1 are known as _______.
alkali metals
True or False: All elements in the modern Periodic Table have gaps.
False
What is the trend of boiling points in noble gases?
Boiling points increase down the group
What are halogens known for?
Their reactivity
What was a limitation of Mendeleev’s Periodic Table?
Some elements had to be swapped to fit in appropriate groups
What does the term ‘reactivity’ refer to in the context of the Periodic Table?
The tendency of an element to undergo chemical reactions
What does the term ‘group’ refer to in the Periodic Table?
A column of elements with similar properties
What elements are in Group 1?
Lithium, Sodium, Potassium, Rubidium, Cesium, Francium
Group 1 elements are also known as alkali metals.
What do Group 1 elements react with?
Oxygen, chlorine, and water
These reactions are significant in understanding alkali metal properties.
What do alkali metals form when they react with water?
An alkali (a solution of their metal hydroxide)
This is a defining characteristic of alkali metals.
Why are Group 1 elements very reactive?
They have one electron in their outer shell that they need to lose
This single electron makes them highly reactive.
What happens to reactivity as you move down Group 1?
Reactivity increases
Larger atomic size and weaker electrostatic attraction contribute to this trend.
What changes occur to the melting and boiling points down Group 1?
Melting point and boiling point decrease
This trend is observed as you move from lithium to francium.
What are Group 7 elements called?
Halogens
Halogens are non-metals that exist as molecules made up of pairs of atoms.
What are the states of matter for the first four halogens at room temperature?
Gas (Fluorine, Chlorine), Liquid (Bromine), Solid (Iodine)
This highlights the physical state changes in halogens.
What happens to reactivity as you move down Group 7?
Reactivity decreases
It becomes harder to gain the one electron to fill the outer shell.
What is a displacement reaction in the context of Group 7 elements?
More reactive Group 7 elements can take the place of less reactive ones in a compound
Example: Fluorine displaces chlorine in a reaction.
Fill in the blank: The reaction of Group 1 metals with water is rather _______.
spectacular
This is often demonstrated in educational settings.
What is the trend for melting and boiling points in Group 7?
Melting point and boiling point increase down the group
This is opposite to the trend observed in Group 1.
True or False: The outer shell is further away from the nucleus in larger atoms of Group 1, making them less reactive.
False
The further distance and additional shells actually increase reactivity.
