Science - Chemistry - Bonding, Structure, and the Properties Of Matter - C2a Flashcards
what is an ion ?
a charged particle
do metal atoms lose or gain electrons ?
lose electrons
when are ions formed ?
when electrons are lost or gained
what type of ion does a metal atom form ?
a positive ion
do non metal atoms lose or gain electrons ?
gain electrons
what type of ion does a non metal ion form ?
a negative ion
how do you calculate the charge of an ion ?
protons - electrons
why are ions formed ?
atoms are trying to get a full outer shell and become stable
elements in the same group have what ?
the same number of electrons in their outer shell
when metals react with non metals what kind of bonding is this ?
ionic bonding
what is ionic bonding ?
oppositely charged ions that are strongly attracted to each other held together by strong electrostatic forces
what are the advantages of using a dot and cross diagram when showing ionic bonding ?
- useful for showing how ionic compounds are formed
what structure do ionic compounds have ?
a giant ionic lattice
what is an ionic compound ?
strong electrostatic forces of attraction between oppositely charged ions which act in all directions
what are the disadvantages of using a dot and cross diagram to display ionic compounds ?
- they do not show the structure of the compound
- they do not show the relative sizes of ions or how they are arranged
what are the advantages of using a 3-D model to display ionic compounds ?
-show relative sizes of ions
- show regular pattern in an ionic crystal
what are the disadvantages of using a 3-D model to show ionic compounds ?
- only lets you see outer layer of the compound
what are the disadvantages of using a ball and stick models to display ionic compounds ?
- ions aren’t shown to scale
- they suggest there are gaps between the ions, which there aren’t
how do you work out the formula of an ionic compound with a dot and cross diagram ?
count up how many atoms of each element there are
how do you work out the formula of an ionic compound using the ball and stick model ?
work out what ions are in the ionic compound then balance the charges of the ions so the overall charge on the compound is 0
what are the properties of ionic compounds ?
- high melting and boiling point due to strong electrostatic attraction between the ions
- solubility, most ionic compounds can dissolve in water
- do not conduct electricity when solid as they are in fixed positions but when melted or dissolved ions are free to move and they can carry electrical charge
what is covalent bonding ?
when a pair of electrons is shared between 2 atoms to get full outer shells
in what type of atoms do covalent bonds occur ?
non metal atoms
what are the advantages of using a dot and cross diagram to show covalent bonds ?
- shows which atoms the electrons in a covalent bond came from
what are the disadvantages of using a dot and cross diagram to show covalent bonds ?
- do not show relative sizes of atoms
- don’t show how they are arranged in space
what are the advantages of using displayed formulas to show covalent bonds ?
- shows how atoms are connected in large molecules
what are the disadvantages of using displayed formulas to show covalent bonds ?
- don’t show 3-D structure
- don’t show which atoms the electrons came from
what are the advantages of using 3-D models to show covalent bonds ?
- shows the atoms and their arrangement in space