A student is given a sample of a blue copper sulfate hydrate. He weighs the sample in a dry covered porcelain crucible and got a

43.62m

Clarification:

Given details:

Energy = 8550J

Mass of bell = 20kg

Unknown:

Height of the bell =?

Solution:

This bell possesses potential energy, which signifies energy at rest due to its positional context.

Potential energy = m g h

where m denotes the mass of the object

g indicates gravity's acceleration

and h stands for the height of the object

Here, we need to isolate for h.

g = 9.8m/s²

     Insert the variables;

        8550 = 20  x  9.8 x h

     As a result, h = 43.62m

learn more:

Potential energy

The reply is: He did not mention any of these topics.

Explanation: Dalton outlined certain postulates for his atomic theory, which are:

1) Matter consists of indivisible atoms.

2) Atoms from different elements combine in fixed proportions to form compounds.

3) The atomic characteristics of a specific element are uniform, including mass. This means all atoms of a given element share the same mass, whereas atoms from different elements exhibit different masses.

4) During a chemical reaction, atoms are not created or destroyed.

5) Atoms of an element are uniform in mass, size, and all other chemical and physical properties.

From these postulates, it is evident that he focused solely on atoms, neglecting subatomic particles or isotopes.