aluminum metal reacts with a solution of arsenic acid to produce hydrogen gas and aluminum arsenate. what happens in this reaction that can be used as evidence to indicate that a chemical reaction has ocurred ?

c is the answer because when something is left after something evaporates that shows the chemical change.

the density of gold = 19.3 g/cm3

the relation between density and mass and volume is

density = mass / volume

given :

mass of gold = 13 g

density = 13g / volume = 19.3

volume = 13 /19.3 = 0.67 cm^3

thus volume of gold nugget = 0.67 cm^3

colorless gas, exhibiting a blue glow when placed in an electric field

b) solid

its a type of rock