GCSE chemistry
What is conservation?
to preserve or stop it from changing
What does the law of conservation of mass state?
matter is neither lost or gained
Name one exception to the conservation of mass
Magnesium plus oxygen equals magnesium oxide
Name one exception to the conservation of mass
Calcium carbonate, plus hydrochloric acid equals carbon dioxide plus water plus calcium chloride
name the equation for nutralisation Reaction
Metal carbonate plus acid equals salt plus water plus carbon dioxide
What is a molecule?
two. More atoms, combined elements or compounds.
What is meant by balanced equation
Location is balanced, and there are the same number of atoms on each type of both sides of the equation
Can you change the little numbers at the bottom of the element, when balancing an equation
Nope
what are the 3 strong chemical bonds?
ionic, covalent and metallic
what are atoms that have gained or lost electrons called?
ions
true or false: ionic bonds occur between positive and negative ions
true
when does ionic bonding occur?
when atoms gain or loose electrons, giving them an overall charge
true or false: ions don't have a complete outer shell (they are stable)
false: they do
fill in the gaps: 1.----- bonding involves a transfer of electrons from a 2.----- atom to a 3.--- ----- atom
1. ionic 2. metal 3. non metal
do metal atoms lose or gain electrons to become positivly charged ions?
lose
do non metal atoms gain or lose electrons to become negative?
gain
what is an ionic bond?
a strong electrostatic force of attraction between a metal positive ion and the negative non-metal ion
what is an ionic compound?
a giant structure of ions
true or false: ionic compunds are held together in all directions by strong ionic bonds
true
name the properties of ionic compounds
have high melting and boiling points
they don't conduct electrictity when solid because the ions cannot move
they do conduct electricity when molten or in a solution because the charged ions are free to move around and carry their charge
what charge do group 1 elements have when they are ions?
1+
what charge do group 2 elements have when they are ions?
2+
what charge do group 7 elements have when they are ions?
1-
what charge do group 6 elements have when they are ions?
2-
what is a disadvantage of the ball and stick model?
it makes it look like the atoms are far apart