Question

Which of the following statements is true?

1. Dalton believed atoms were made mostly of empty space.
2. Plasmas have a net negative charge.
3. The number of protons in an element is always equal to the number of neutrons.
4. Solids have a fixed mass, volume, and shape.

Answer 1

solids have a mixed mass, volume, and shape.

Answer 2

Answer: Solids have a fixed mass, volume, and shape.

Explanation: Solids are the substances which have fixed shape, fixed volume and mass due to its close packed structure.

Dalton explained that all the elements are made up of small indivisible particle known as Atoms but after some time this was proved wrong as atoms is not indivisble, it conatins sub atomic particle like electrons, protons, neutrons etc.

Plasmas are considered as the fourth state of matter which contains equal quantity of positive ions and negative electrons.

The number of protons are equal to the number of electrons. The sum of number of protons and neutrons make the atomic mass quantity.