section one random questions Flashcards
what happens when a solid is heated?
the particles vibrate more and gain more energy, they start moving about randomly more. it expands when heated
what happens with the bromine experiment and air in a jar?
the random motion of the particles makes the gases mix
what’s the mass of an electron
1/2000 or negligible
what is filtration used for?
to separate a insoluble solid from a liquid
what is crystallisation used for?
used to separate a soluble solid from a solution
how would you separate rock sand using filtration techniques?
grind the rock salt in a pestle and mortar, dissolve in a beaker and stir, filter through filter paper in a funnel, evaporate in an evaporating dish
what is the force that holds together ions in a ionic compound?
electrostatic attraction
what are the forces that hold together electrons/ions in a covalent bond?
intermolecular bonds of attraction in a simple molecular covalent bond
and covalent bonds in a giant covalent structure
what is a double covalent bond
eg. c=c between the same element
how do you write ions?
Na+
atoms in a molecule…
are held together by strong forces of attraction
how many covalent bonds does graphite form?
3
what form is a precipitate?
solid
what is relative atomic mass?
the average mass of all isotopes of an element compared to the mass of 1 atom of carbon 12?
