A. what is the basic building block of matter?

b. list the three types of particles that make up an atom. describe each particle based on its charge and relative mass.

c. how can you distinguish an ion from an atom?

d. compare the number of protons with the number of electrons in a negative ion

e. j. j thomson experimented with cathode ray tubes and created the plum-pudding model of the atom. how was the model he proposed different from the previous model of the atom? write one or two sentences to describe the evidence on which he based his conclusions?

a. atoms are the basic building blocks of matter. The atom is made of electrons and protons. It contains the chemical identity of an element.

b. Three types of particles that make up an atom are:

electrons - these are negatively charged particles and lightest constituents of an atom.

protons are positively charges and is 1873 times heavier than an electron.

Neutrons are neutral particles having mass equivalent to mass of proton.

Protons and neutrons exist in the center of an atom in nucleus and electrons revolve around the nucleus.

c. An atom is a neutral entity where as an ion is charged. An ion has excess of electrons or lacks electrons due to which it has negative or positive charge. An atom has an equal number of electrons and protons.

d. In a negative ion, the number electrons is greater than number of protons. The atom when gains electrons becomes negative ion.

e. John Dalton proposed Solid sphere model in which tiny invisible particles constitute matter. These invisible particles are atoms and these are indivisible.

a) Everything's made of atoms! Despite the fact that they still can be split to nucleons and quarks...

b) From lightest to the heaviest: electrons (charge -1), protons (+1), neutrons (0 charge).

c) Atoms are electrically neutral and ions doesn't

d) Negative ion has more negative charges - electrons, so they are in majority.

e) In Thomson's model of atom charges were uniformly spread in the atom's volume. He thought that this model is enough to describe atoms' neutrality.

d. air pressure decreases as altitude increases.