Chemistry 4.1 Atomic structure and the periodic table

Flashcards about atomic structure and the periodic table.

Atom

Smallest part of an element that can exist.

Elements

Made of only one type of atom.

Compounds

Formed from elements by chemical reactions.

Mixture

Two or more elements or compounds not chemically combined together.

Democratus's Model of the Atom (400 AD)

Atoms were tiny indivisible spheres

Dalton's Atomic Theory (1803)

Matter is made up of extremely small particles called atoms.

J.J. Thomson's Contribution (1897)

Discovered the electron, leading to the plum pudding model of the atom.

Rutherford's Model (1911)

Atom contains a central nucleus and that the nucleus was charged.

Bohr's Model (1913)

Electrons orbit the nucleus at specific distances.

Rutherford's Discovery (1917)

Positive charges of any nucleus are made up of particles called protons.

Chadwick's Experimental Work (1932)

Existence of neutrons within the nucleus.

Atomic Number

Number of protons in an atom of an element

Isotopes

Atoms of the same element with different numbers of neutrons.

Relative Atomic Mass

Average value that takes account of the abundance of the isotopes of the element.

Periodic Table

Elements are arranged in order of atomic (proton) number

Metals

React to form positive ions.

Non-metals

Do not form positive ions.

Noble Gases

The elements in Group 0 of the periodic table.

Alkali Metals

The elements in Group 1 of the periodic table

Halogens

The elements in Group 7 of the periodic table

Transition Metals

Metals with similar properties which are different from those of the elements in Group 1