Textbook Unit 1.3 Flashcards
(33 cards)
what is it called when different elements join or bond together
compound e.g. H2O
what are the two main types of bonding in compounds
ionic and covalent
ionic bonding is when ions are held together
by electrostatic forces
when are ions formed
when one or more electrons are tranferred from one atom to another
what r the most simplest ions
single atoms that have lost or gained electrons so they have a full outer shell
groups go down the periodic table
periods go across the periodic table
what does electrostatic attraction hold?
positive and negative ions, when atoms are held like this, it is called ionic bonding
ionic bonding happens between?
metals and non metals
what are compound ions
made from a group of atoms with an overall charge
what are examples of compound ions LEARN CHEM FORMULAS
- Sulfate
- hydroxide
- nitrate
- carbonate
- ammonium
what shud you look at to find the formula of an ionic compound?
its charges
what are ionic compounds usually made up of
a positively charged part and a negatively charged part
what is the overall charge of any compound and why
zero BC all negative charges in compound must balance all positive charges
what are some examples of regular ions?
- sodium
- magnesium
- chlorine
- oxygen
You have to look at the charge of individual to work out the formula of an ionic compound
what is an ionic crystal
giant lattices ( structures) of ions
why is the structure called giant
because its made up of the same basic unit repeated over and over again
what is an example of a giant ionic lattice structure
sodium chloride
In sodium chloride, the positive sodium ions and the negative chlorine ions are packed together
what shape is the sodium chloride lattice
cube shaped
what does the different structure of ionic compounds determine
their physical properties
when do ionic compounds conduct electricity and why
when they’re molten or dissolved
BC
- ions in a liquid are free to move (and they carry a charge)
- in a solid the ions are in a fixed position by strong ionic bonds so cant pass the charge
why do ionic compounds have high melting points
because giant ionic lattices are held together by strong electrostatic forces
- takes alot of energy to overcome the forces so melting points are very high e.g. 801 degrees for sodium chloride
why do ionic compounds usually dissolve in water
water molecules are polar - part of the molecule has a small negative charge and other bits have small positive charges.
- these charged parts pull ions away from the lattice causing it to dissolve
