pERODIC 4 Flashcards
(26 cards)
What is the periodic table?
A list of elements arranged in order of increasing atomic (proton) number.
How many groups and periods are in the periodic table?
18 vertical groups (columns) and 7 horizontal periods (rows).
What is Group 1 called?
Alkali metals (excluding Hydrogen).
What is Group 2 called?
Alkaline earth metals.
What is Group 7 called?
Halogens.
What is Group 0 called?
Noble gases or inert gases.
What are valence electrons?
Electrons in the outermost shell of an atom.
How is valency calculated?
If valence electrons ≤ 4 → valency = valence electrons. If > 4 → valency = 8 - valence electrons.
What determines an element’s group number?
The number of valence electrons.
What determines an element’s period number?
The number of occupied electron shells.
What happens when an atom loses electrons?
It becomes a positively charged ion (cation).
What happens when an atom gains electrons?
It becomes a negatively charged ion (anion).
Why do elements in the same group have similar chemical properties?
They have the same number of valence electrons.
What are the physical properties of alkali metals?
Soft, low density, low melting and boiling points, good conductors.
What are the chemical properties of alkali metals?
React vigorously with water, chlorine, and oxygen.
How does reactivity change in Group 1?
Reactivity increases down the group.
What are the physical properties of halogens?
Coloured, poisonous, non-metals, diatomic molecules.
How does reactivity change in Group 7?
Reactivity decreases down the group.
What are the properties of noble gases?
Colourless, unreactive, full outer shells, monatomic gases.
Where are metals and non-metals located in the periodic table?
Metals on the left, non-metals on the right.
What are metalloids?
Elements with properties of both metals and non-metals, found along the ‘stair-step’ line.
What are the properties of transition metals?
Hard, high melting points, form coloured compounds, variable oxidation states.
Do metals conduct electricity?
Yes, in all states.
Do non-metals conduct electricity?
No, except graphite.
