2.1 ELEMENTS

• The smallest building blocks of matter are atoms.

• What is the difference between an atom and an element?

• An element is a pure substance that cannot be broken down or separated into simpler substances.

• An element is a type of atom.

Example:Copper is an element,

An atom of copper is the smallest possible piece of copper you can have, that still has all the properties of copper.

CHEMICAL SYMBOLS

• Each element has a name, but the names are different depending on the language you speak.

• Symbols provide an international language so all chemists around the world can share their discoveries.– If symbol is only one letter capitalized– If symbol is 2 letters 1st capitalized, 2nd lower

case• Eg: Oxygen = O Mercury = Hg

INVESTIGATING THE STRUCTURE OF THE ATOM

• Every atom is composed of 3 types of particles:– Protons: positively charged– Neutrons: no charge– Electrons: negatively charged

• Protons and neutrons are found in the nucleus• Electrons circle the nucleus in particular

energy levels

Rules for atomic particles:

1. # protons = # electrons2. Atomic number = # protons3. Atomic mass = the mass of an average atom

of an element4. Ion charge = an electric charge that forms on

an ion when it gains or loses electrons.

Assignment:

• “Learning chemical symbols” worksheet• Reading check page 47• CYU page 51 #1-18• “Adopt-an-element” project

Who created the periodic table?

• Dmitri Mendeleev• He arranged it by grouping elements with

similar properties together• The periodic table contains an amazing

amount of information

Info on a square in the Periodic Table:

• Some elements have multiple ion charges as they form ions in more than one way.

Trends in the periodic table:

• Elements are arranged in order of atomic number

• THEY ARE NOT ARRANGED BY ATOMIC MASS!!

Trends in the periodic table:

• Elements on the LEFT side of the table mostly form POSITIVE ions– This means they LOSE ELECTRONS

Trends in the periodic table:

• Elements on the RIGHT side of the table mostly form NEGATIVE ions– This means they GAIN ELECTRONS

Trends in the periodic table:• Elements

in the same column usually have similar ion charges.

Trends in the periodic table:

Metals, Non-metals and Metalloids…

• Elements are clumped in groups that have similar properties

• Table 2.2 (pg.55) shows the properties that each of these groups have in common.

Trends in the periodic table:• Within each of these groupings are columns of

elements with very similar properties. – These are called families

Assignment:

• Reading Check page 57• 2.2 Worksheet• Complete “Adopt an Element” research