Answer:
it can show how much green is left. and how climate change is going, and the cloud shows how much oxygen is left in the air.
We can define density as the mass per unit volume;
D = M/V
here density is given that is 19.3g/cm³
and dimensions are given that is volume = 4.72 cm x 8.21 cm x 3.98 cm = 154.23 cm³
Now from the formula'
M = D x V
putting the values of density and volume
Mass = M = 19.3g/cm³ x 154.23 cm³ = 2976.64 g
Salt, sodium ion and buffer
Buffer is the best answer : Baking soda
<span>Buffers: A buffer is a compound that limits the change in hydrogen ion concentration (and so pH) when hydrogen ions are added or removed from the solution. It may be useful to think of the buffer as being like a sponge. When hydrogen ions are in excess, the sponge mops up the extra ions. When in short supply the sponge can be squeezed out to release more hydrogen ions</span>