Which of the following statements is true?
a. dalton believed atoms were made mostly of empty space
b. plasmas have a net negative charge
c. the number of protons in an element is always equal to the number of neutrons
d. solids have a fixed mass, volume, and shape

D. Solids have a fixed mass, volume, and shape

Explanation:

solid have fixed volume, mass and shape due to this they are closely packed.

The molecules in the solid stay in fixed points and they are tight together.

Dalton explained that all the elements are made up of atoms.

Plasmas contain both positive ions and negative charges in equal quantity.

The number of protons in an element is always equal to the number of electrons.

Thus option(D)  Solids have a fixed mass, volume, and shape is the correct answer.

weight of any object is given by

w = m*g

where m is mass of the object and g is the acceleration due to gravity.

for earth the value of g is 9.8 m/s^2 so

w=117.6 n m=12 g=?

117.6=12g => g=9.8 m/s^2

which is the force of gravity on earth.