solid,liquid,gas
An example of mixure
air,tap water...
electron
What is the symbol of sulfur
S
What is the Ar of Cu
63.5/64
give two coversions that absorb enegry
melting, boiling, evaporation, sublimation, any two of them
Definition of compound
two or more elements chemically combine
What consist of (组成) nucleus?
proton and neutron
which is the location of Ar
Period 3, group 0
What is the Mr of CaCO3
Ca=40, C=12, O=16
40+12+16x3=100
solid<liquid< gas
list at least three ways for separation
Why atom is electrically neutral?
number of protons =number of electrons
What is the element oin group 4 period 4
Ge/Germanium
2x32=64g
describe what is solute, solvent and solution
solute: sth dissolves
solvent:sth dissolves in
solution: the mixture formed when solute dissolves in solvent
fractioanl distillation
What is the Ar of Chlorine, when the abundance of 35Cl is 75% and 37Cl is 25%
35x0.75+37x0.25=35.5
they all have 3 electrons in their outershell
A compound contains 0.78g K, 1.1g of Mn and 1.28g of O, what is the empirical formula
Describe the arrangement and movement of particles in solid state
arrange regularly & packed closely and vibrate at fixed position
why we need to draw the baseline with pen
ink will move with solvent/ pencil wont move
the outershell is full, no tendency to gain or lose electrons
list at least three properties of metals
shiny, conduct electricity,conduct heat, form basic oxide,malleable,ductile, form ionic compound, any three of them
Finding the empirical formual of a compound containing 82.7% C and 17.3% H by mass
C2H5