1. Which of the following gases reacts with an alkaline solution? A Argon
B Oxygen
C Ammonia
D Nitrogen dioxide

They are like other investigations? say there was a murder u have to do blood test and finger prints which run through a lab. 

Answerδh > 0explanationc₆h₆  (s)  → c₆h₆ (l)if you are changing it from a solid to a liquid, you are pretty much melting the solid. this requires heat energy. therefore, the reaction is endothermic (takes in energy); the system enthalpy increases as the reaction proceeds: δh > 0.

Ahigh energy (high speed) particle (alpha or beta or neutron) are shot at the target;