1. Metals, Nonmetals, Metalloids and the Periodic Table

2. The First Periodic Table
In the 19th century Dmitri Mendeleev designed the first periodic table of elements, in order of increasing atomic mass: the average mass of all the isotopes of a given element.
Today our table is in order of increasing atomic number: number of protons in the nucleus.
The atomic mass for most elements ends in a _______, because most elements are made up of a random mixture of isotopes. Atomic mass is found by calculating a weighted average of the percentages of all isotopes in a given element.

4. Organizing the Periodic Table
The properties of an element can be predicted from its location in the periodic table.
Periods: the __________ that contain a series of different elements. There are seven periods.
Groups (families): are ___________ of elements that share certain properties. They are labeled group 1 to 18 and are named after the 1st element in that group.

5. Metal Groups
A metal is a class of elements characterized by its physical and chemical properties.
Physical Properties
Luster: __________
Malleability: ability to be hammered/rolled flat
Ductility: ability to be pulled/stretche into a long wire
Conductivity: ability of an object to transfer _______ or __________ to another object
Chemical Properties
__________: the ease with which an element combines with another
Most metals react by losing electrons to other atoms.

6. Metals by Group
The reactivity of metals decreases from left to right across the periodic table, because elements have more valence electrons.
Group 1: Alkali Metals
React by losing one electron, and very reactive
Group 2: Alkali Earth Metals
React by losing two electrons
Groups 3-12: Transition Metals
More stable metals
Groups 13-15: Metals in Mixed groups
In these groups only SOME elements are metals

7. Synthetic Elements
Elements above #92 are made artificially when nuclear particles are forced to crash into one another at high speeds, using a particle accelerator.
When atoms move this fast their atomic nuclei can sometimes bombard other nuclei and combine into a single nucleus with extra protons.
Example: plutonium is made by bombarding uranium nuclei in a reactor.

8. Nonmetals
A nonmetal is an element that lacks the properties of metals.
Poor conductors of electricity/heat but they are reactive with many metal elements.
_______ or share electrons in chemical reactions.
Group 14: Carbon Family
Elements in this family gain, loses, or share four electrons.
Group 15: Nitrogen Family
React by gaining three electrons
Group 16: Oxygen Family
React by gaining _______ electrons
Group 17: Halogen Family
Highly reactive elements, gain one electrons
Group 18: Noble Gases
Highly stable and unreaactive

9. Metalloids Share characteristics with _______ and nonmetals.
There are a total of ____ metalloids.
Metalloids are solid, brittle, and hard.
Most useful property is their varying ability to conduct electricity.
They are used to make semiconductors:
substances like computer chips that can conduct electricity under some conditions but not under other conditions.
Silicon (Si)f is the most common metalloid. It is found in sand, glass, and computer chips.