Periodic table Flashcards
Periodic table
Elements in a table with order of increasing atomic number
Top of the f block (below transition metals)
Lanthanides
Bottom of f block(below transition metals)
Actinides
Properties of metals
Shiny solids, good conductors(heat+elec) malleable+ductile, generally high melting and boiling points, react with acid to give off hydrogen gas
Metalloids
zigzag down from B including Ge and Sb. Solid at room temp, not malleable or ductile, resist flow of electricity. When in chem reac with metals, they behave like nmetals. When in chem reac with nmetals they behave like metals.
Non metals
Dull, brittle, Insulators(Graphite is only exception - it is a conductor). Gaseous nmetals low melting + boiling points. Do not react with acids
Metallic nature decreases…
Across the period and increases down a group
Metal reactivity increases…
Down a group
Non metal reactivity increases…
Up a group
Density and melting points increase…
Down a group
Non metals become more metallic as…
Down a group
Ionization energy
Energy needed per mole to remove e- from an atom in gaseous phase
First Ionization energy
energy needed per mole to remove 1st e- from atom in gaseous phase.
Successive Ionization energy…
Requires increasing amount of energy to remove successive e- as a result of atom becoming progressively more positively charged from e removed.
Noble gases
High ionization energies due to full outer shell which explain why they dont react under normal circumstances
Causes of trends in io energy(not first io energy)
Valence electrons get further from nucleus resulting in weaker force of attraction require less energy to remove valence electron from atom and increased shielding effect - core electrons repel valence electrons. More core electrons down a group, shielding effect increases.
Electron Affinity
Amount of energy released per mole when an atom or molecule gains an electron to form a negative ion. Halogens most likely to form negative ions. F has highest e affinitiy.
Electronegativity
Tendency of atom to attract shared pair of e- to itself. More protons - stronger attraction on a bonding pair of electrons.
Ion
Charged particle
Cation
Positive ion - lost e-
Anion
Negative ion - gained e-
Atomic radius
Measure of size of atom
Ionic radius
measure of size of cation or anion
These increase from left to right across period and decrease as u go down group
Electronegativity, e- affinity and io energy
Atomic and ionic radius trends
Bigger as u move down group and smaller across period
