The height of a place from the sea level is called​

Mean level

The elevation is the height of point that is found above the sea levels and these levels is called as the average or the mean level and has an average height above the surface and can be seen the rise and the fall of the tides in an open coastal area over a period of 19 years

Altitude, like elevation, is the distance above sea level. ... This is called indicated altitude, and is measured by an instrument called an altimeter. As altitude rises, air pressure drops.

Explanation:

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e

- lead + phosphoric acid = hydrogen + lead(ii) phosphate