Chapter 4.1 and 4.2 atomic structure

Everything in the world is made of less than 100 types of atoms called elements.

Everything in the world is made of less than 100 types of atoms called elements they combine to make compounds like letters of the alphabet make words

In a chemical reaction, one substance changes to another by reorganizing the way the atoms are attached to each other

• In 1803, John Dalton proposed a theory which accurately described and predicted chemical behavior.

• Dalton’s four postulates are still accepted today (with a few modifications)

Dalton’s atomic theory- 4 postulates all elements are composed of tiny indivisible particles called atoms.

Dalton’s atomic theory- 4 postulates all elements are composed of tiny indivisible particles called atoms.

Dalton was wrong about the “indivisible” part, but the rest of this tenet is still fundamental to chemistry.

Dalton’s atomic theory- 4 postulates atoms of the same element are identical. The atoms of any one element are different from those of any other element.

Dalton’s atomic theory- 4 postulates atoms of different elements can physically mix together or can chemically combine in simple whole-number ratios to form compounds.

Dalton’s atomic theory- 4 postulates chemical reactions occur when atoms are separated, joined, or rearranged. Atoms of one element are never changed into atoms of another element in a chemical reaction.

Atoms are composed of protons, neutrons, and electrons.

Atoms are composed of protons, neutrons, and electrons.

Protons and neutrons are found in the tiny nucleus of the atom.

The cloud that they form is the majority of the atom’s size.