Answer:
sodium hydroxide and hydrochloric acid is the reactants
The layer of atmosphere that MOST planes fly in is called the troposphere.
It is a trial aimed to reduce bias during an experiment. An example would be a sugar pill, something that has no real effect so that the results of the true trial can accurately be compared. Its like a control group.
The volume of copper : 3.24 ml
<h3>Further explanation
</h3>
Density is a quantity derived from the mass and volume
Density is the ratio of mass per unit volume
With the same mass, the volume of objects that have a high density will be smaller than objects with a smaller type of mass
The unit of density can be expressed in g/cm³ or kg/m³
Density formula:

ρ = density
, g/cm³ or kg/m³
m = mass
, g or kg
v = volume
, cm³ or m³
A common example is the water density of 1 gr / cm³
The density of copper : 8.96 gr/ml
mass of copper : 29 g
then the volume :
