Bonding and structure Flashcards
what are ions
charged particles
what kind of ion do non metals make
gain electrons so negative ions
why are ions formed
the atom is trying to get a full outer shell of electrons
what is the relation between group number and the ion formed by those atoms
all produce ions with the same charge
what is ionic bonding
metals react with non metals, metals loses an electron and non metals gain one. This causes atoms to have opposite charges so they are strongly attracted to one another. this holds the ions together in an ionic compound
how do you represent the charge of an ion in a dot and cross diagram
e.g 1+ or 3+ in the top corner outside the bracket
ionic compounds have a structure called what
giant ionic lattice
pros and cons of dot and cross diagrams
good for showing how ionic compounds are formed
dont show structure of compound, relative sizes or how they are arranged
pros and cons of 3d models
show relative sizes of ions and the pattern in an ionic crystal.
only let you see outer layer of compound
pros and cons of ball and stick models
show regular pattern, show how ions are arranged, suggest crystal extends beyond what is shown, show relative sizes
sometimes ions are not shown to scale and they suggest gaps are between the ions
what is the boiling points like for ionic compounds
high
what is the solubility like of ionic compounds
most easily dissolve in water
what is the electrical conductivity of ionic compounds like
don’t conduct when solid because ions are held in fixed positions
do when melted or dissolved because then ions are free to move
what is covalent bonding
a pair of electrons is shared between 2 atoms to get full outer shells.
why are covalent bonds strong
positively charges nuclei is attracted to shared electrons by electrostatic forces
what atoms use covalent bonds
non metals
pros and cons of displayed formula
shows how atoms are connected in large molecules
dont show 3d structure or which atoms the electrons in the covalent bond have some from
what are simple molecules
a few atoms joined by covalent bonds.