Periodic Table Flashcards
What is a molecule
Two or more atoms bond by sharing electrons
Compound
When atoms are from different elements
Mass number
Number of protons-number of neutrons
Neutrons
Mass number-atomic number
Isotopes
Atoms of the same element can have different mass numbers. They have same atomic number but different number of Nuclei
Maximum number of electrons for each shell
Shell1:2
Shell2:8
Shell3:18
Shell4:32
Valence electrons
Electrons in the outermost shell of an atom
Core charge formula
Number protons - inner shell electrons
Atomic radius definition
Distance from Centre on atoms to valence electrons
Electronegativity trends
High for non metals
Group 18 no electronegativity
Less pull when valence electrons further from nucleus
First Ionisation energy
The energy required to remove first valence electron from atom
First Ionisation Trends
Decreases going down a group
Increases across a period
Metallic character
Easily lose electrons, conducts electricity and shiny
Non- metallic character
Non- metals, gain electrons
Metalloids
Mix of both metallic and non metallic