Answer: Hydrogen gas will be given off
Explanation:
Whenever a metal reacts with an acid, a salt of the metal is formed and hydrogen gas is given off.
For instance: The reaction of Zinc metal on Hydrochloric acid.
Zn(s) + 2HCl(aq) ---> ZnCl2(aq) + H2(g)
From the equation provided, hydrogen gas is given off as a by-product
Answer:
nine
There are nine orbitals in the n = 3 shell. There is one orbital in the 3s subshell and three orbitals in the 3p subshell. The n = 3 shell, however, also includes 3d orbitals. The five different orientations of orbitals in the 3d subshell are shown in the figure below.
Explanation:
Answer : The amount of formaldehyde permissible are, 
Explanation : Given,
Density of air =

First we have to calculate the mass of air.



Now we have to calculate the amount of formaldehyde.
Permissible exposure level of formaldehyde = 0.75 ppm = 
Amount of formaldehyde in 7.2 g of formaldehyde = 
Amount of formaldehyde in 7.2 g of formaldehyde = 
Thus, the amount of formaldehyde permissible are, 
The answer to this great question is C.Watershed