Why do you need to use a student bench hood in the preparation of KAl(OH)4?

Exothermic,  physical change after it is already baked

Must be negative.substance increases

The answers are 3.c kelvin4.b liquids only

B.1 - hydrogren-1 can only mean there is 1 neutron. it's obvious there is 1 proton or else it wouldn't be hydrogen, so they wouldn't put a number after it unless they were indicating the number of neutrons