What question could be asked to help determine whether the solar system is heliocentric or geocentric?
A) Why does the moon seem larger than the sun when it is further away?
B) Why can objects be seen orbiting other planets ( i. e. Jupiter’a moon)?
C) Why do some planets seem to change direction/move backward at times?
D) How do the stars/visible planets seem to move across the sky?

Can anyone (a-level) a student was analysing a carbonate compound, mco3, containing an unknown group 2 metal, m. the student carried out thermal decomposition on 0.730g of the carbonate and measured the volume of gas produced. mco3 (s) mo (s) + co2 (g) the student collected and measured 120cm3 of carbon dioxide. 1 mol of carbon dioxide occupies 24 000 cm3 under these conditions. calculate the molar mass of the group 2 carbonate and hence deduce the identity of the group 2 metal, m.

Energy defines the different "states" of matter. in no more than 3 sentences, describe the amount of kinetic energy that each of the 3 states of matter possesses and relate that to the atom/molecular motion of each "state".

Which type of intermolecular attractions holds ammonia molecules together with other ammonia molecules?