A scientist performs an experiment where she measures the mass of a piece of metal, pours acid onto the metal, washes the metal, and then re-measures the mass of the metal. The scientist repeats the experiment several times
each time increasing the amount of acid used.
The dependent variable in the experiment is the

A. Initial mass of the metal

B. Final mass of the metal

C. Amount of acid used

D. Washing the metal

B (Final mass of the metal)

Explanation:

The independent variable in this experiment is the amount of acid the scientist pours on the metal, and the only variable in the list dependent on the amount of acid poured on the metal is the final mass of the metal. Therefore, the final mass of the metal is the dependent variable in the experiment.

answer: the rate of diffusion increases with increase in temperature.

increase in temperature, increases the molecular/particles speed (kinetic energy. diffusion means movement of particles through the material.

generally, the heavier the particle the more it interacts with the environment and more the temperature matters. so higher temperature results in higher diffusion.

we can conclude that the melting point of table salt is above room temperature (it's actually 801 deg c). the melting point of mercury must be below room temperature (- 39 deg c).