During an experiment vinegar was added to baking soda. The following observations were recorded. Observation 1: The container with the reaction mixture feels cooler.
Observation 2: Gas bubbles are released.
Based on the observation, justify the type of change (physical or chemical) that took place. (4 points)

Modern weaponry has increased the number of deaths in wars and violent conflicts.

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.

Use the measurements in the table to determine which unidentified metal has the highest density. metal volume mass a 10.5 cm3 122 g b 14.2 cm3 132 g c 16.1 cm3 115 g d 12.7 cm3 126 g