Hi, thank you for posting your question here at Brainly.
The independent variable is the variable that you have control of. By changing this variable, the other dependent variables will consequently change. Thus, the independent variable nature of the mercury oxide sample used.
Sound is the movement. Hope this helped. Have a great day! :D
The symbol for the hydronium ion is H3O+.
An hydronium ion is usually formed when an acid is present in water. The hydronium ion is made up of three atoms of hydrogen and one atom of oxygen, thus an hydronium ion is a water molecule which has gained an extra positive hydrogen ion.