Thomson's experiments were significant in that they questioned a. whether matter is made up of atoms. b. whether the atom has a positive or negative charge. c. whether atoms will form compounds with other atoms. d. whether the atom could be broken up into smaller units.

The correct answer is option B.

Explanation:

J.J Thomson was an English physicist who had given the plum pudding model of the atom in 1904. In which he described about the existence of two subatomic particles which are protons (positive particles) and electrons (negative particles).

In his model atom was considered to be a pudding or bed of positive charge in which negative particles are present same as as plum on the pudding.

it is to be noted that an alpha particle is an helium nucleus. so it contains 2 protons 2 neutrons and has a mass number of 4. when alpha decay particles are ejected from the nucleus it gets transformed into an atom which has atomic number less than 2 and a mass number less than 4.

an equation that could represent alpha decay is radium 226 decay of alpha particle forms radon 222.

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c, liquids evaporate, creating a gas