Periodic Table retrieval questions Flashcards
How is the modern Periodic Table ordered?
by atomic number
The modern Periodic Table is arranged in order of increasing atomic number.
How were the early lists of elements ordered?
by atomic mass
Early versions of the Periodic Table were organized based on atomic mass.
Why did Mendeleev swap the order of some elements?
to group them by their chemical properties
Mendeleev rearranged elements to better reflect their chemical behavior.
Why did Mendeleev leave gaps in his Periodic Table?
leave room for elements that had not yet been discovered
Mendeleev predicted the existence of undiscovered elements.
Why do elements in a group have similar chemical properties?
have the same number of electrons in their outer shell
The outer shell electron configuration determines chemical properties.
Where are metals and non-metals located on the Periodic Table?
metals to the left, non-metals to the right
This arrangement highlights the distinction between metals and non-metals.
What name is given to the Group 1 elements?
alkali metals
Group 1 elements are known for their reactivity, particularly with water.
Why are the alkali metals named this?
they are metals that react with water to form an alkali
Alkali metals produce hydroxides when they react with water.
Give the general equations for the reactions of alkali metals with oxygen, chlorine, and water.
- metal + oxygen → metal oxide
- metal + chlorine → metal chloride
- metal + water → metal hydroxide + hydrogen
These reactions demonstrate the typical behavior of alkali metals.
How does the reactivity of the alkali metals change down the group?
increases (more reactive)
Reactivity increases due to the increasing atomic size down the group.
Why does the reactivity of the alkali metals increase down the group?
they are larger atoms, so the outermost electron is further from the nucleus
Increased distance from the nucleus results in weaker attraction for the outermost electron.
What name is given to the Group 7 elements?
halogens
Halogens are known for their reactivity and tendency to form salts.
Give the formulae of the first four halogens.
F₂, Cl₂, Br₂, I₂
These are the diatomic molecular forms of the first four halogens.
How do the melting points of the halogens change down the group?
increase (higher melting point)
Halogens exhibit an increase in melting points as you move down the group.
How does the reactivity of the halogens change down the group?
decrease (less reactive)
Reactivity decreases due to the increasing atomic size and shielding effect.