If a ball to be used in a club champions league has a mass of 0.5 kg and
raduis of 0.lm,
has
Calculate
i) its volume
ii)it's weight
iii)it's density if it has a volume of 25 centimere cube
(kilograms/metre cube)​

Write a net ionic equation to show that hydrofluoric acid, behaves as an acid in water.

The human eye contains a molecule called 11-cis-retinal that changes shape when struck with light of sufficient energy. the change in shape triggers a series of events that results in an electrical signal being sent to the brain that results in vision. the minimum energy required to change the conformation of 11-cis-retinal within the eye is about 164 kj/mol.

Ineed ! i have no clue how to do this problem.