Which of the following summertime activities consists solely of physical change?
a. making a sandcastle out of water and sand
b. letting the sun turn your skin a toasty brown
c. eating and digesting a sandwich at a picnic
d. lighting a beachside bonfire for your friends

The pressure inside a hydrogen-filled container was 2.10 atm at 21 ? c. what would the pressure be if the container was heated to 92 ? c ?

How would the number of moles (n) of o2 change if the atmospheric pressure doubled but all other variables stayed the same

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.