The diagram below shows students set-up for the preparation and collection of oxygen gas X
Oxygen gas
Sodium
peroxide
(a) Name substance X used
(b) Write an equation to show the reaction of sodium peroxide with the substance named in 1

Joan writes four numbers on the board in standard form, and then she writes their scientific notation

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.

Acompound has a molecular weight of 12.124 atomic mass units and the empirical formula c3h40. what is the molecular formula of the compound?