Chemistry Chapter 2

1.) Elements are composed of extremely small particles called atoms.
2.) All atoms of a given element are identical, having the same size, mass and chemical properties. The atoms of one element are different from the atoms of all other elements.
3.)Compounds are composed of atoms of more than one element.
4.)A chemical reaction involves only the seperation, combination or rearrangement of atoms it does not result in their creation or destruction.

Dalton's third theory: different samples of the same compound always contain its component elements in the same proportion by mass.

Also relating to Dalton's third theory: if two elements can combine to form more than one compound, the masses of one element that combine with a fixed mass of the other element are in ratios of small whole numbers.

Dalton's forth theory: matter can be neither created nor destroyed.

The basic unit of an element that can enter into chemical conbination. An atom is made up of protons, neutrons and electrons. (In summary atoms (electrically neutral) are composed of three subatomic particles)

An electron is a negatively charged particle. It has a mass of 9.10 x 10(^-28) g, charge of -1 and relative mass of 0

The emission and transmission of energy through space in the form of waves.

Abreviated as C it is the unit of electric charge (i.e.-10g/C 10 grams per coulomb)

Atoms are composed of -ve charged particles (electrons) and that they are electrically neutral. He also established a ratio of mass to electric charge (mass/charge) for an electron.

Determind the electric charge (-e) of the electron and combined with Thomson's findings was able to show that the electron has mass (mass shows exsisitance)

The plum pudding model which consists of little entities (electrons) in a positive charged sphere.

Rutherford discovered positively charged particles (protons) in an atom are all concentrated in a dense central core called the nucleus thus completely destroying Thomson's plum pudding model.

That the nucleus of an atom also contains electrically neutral particles called neutrons.

A positively charged particle in the nucleus of an atom. A proton has a +1 charge, actual mass 1.7 x 10 (^-24) g and relative mass (relative meaning when compared to) of 1.

A electrically neutral particle having a mass slightly greater than that of protons. A nuetron has a 0 charge,actual mass 1.7 x 10 (^-24) g and relative mass (relative meaning when compared to) of 1.