Elements are the building blocks of matter Chapter 2 Elements are the building blocks of matter

Chapter 2 Objectives In this chapter, you will Distinguish between metals, non-metals, and metalloids Explain the organization of the periodic table Predict the properties of a family of elements in the periodic table Compare the characteristics and atomic structures of an element Draw Bohr model diagrams

2.1 - Elements There are about 92 pure substances called elements that occur naturally Each element is made up of only one kind of atom All other forms of matter are made from combinations of elements eg. H2O and CO2

Elements Each element is represented by a one- or two-letter symbol Common elements include; Hydrogen (H) Iron (Fe) Oxygen (O) Sodium (Na) Chlorine (Cl) Mercury (Hg) Silver (Ag) Silicon (Si)

Chemical Symbol There are 118 different elements (92 naturally occurring and others synthetic (man made) Each element symbol consists of one or two letters The first letter is always capitalized, whether it is a single letter or two lettered element, the second letter is always lower case.

Chemical Symbol The symbols on the Periodic Table are universal (used world-wide) Symbols come from Latin (or Greek) words CAPITALIZE the first letter, lower case 2nd letter (if it is needed) e.g. No vs. NO (No = nobelium - an element VS NO = nitrogen monoxide – a compound) Check out page 44 for some highlights!

Elements How do we separate one element from one another? From Chapter 1, we looked at physical properties like state, color, melting and boiling points, malleability, ductility, magnetism, crystallinity, density etc Each element has its own set of physical properties as well as chemical properties. We use Chemical properties to describe a substance’s ability to react chemically with other substances to form new products

Elements (pg. 44) Your textbook talks about 8 specific common elements All elements are separated into either metals or non-metals by the staircase on the period table Metals are typically hard, shiny, malleable, ductile and good conductors of heat and electricity Non-metals tend not to have these properties and are usually gases or brittle solids at room temperature

Elements Meet the Elements

Hydrogen (H) Colorless, odourless, tasteless, and highly flammable gas It is the lightest element Hydrogen makes up over 90% of the atoms in the universe Lighter than air

Iron (Fe) Very strong metal Combines with carbon to make steel Iron is very ductile (wires in foundations) Rusts when exposed to oxygen and water

Oxygen (O) Non-metal Gaseous element Combines with sugar in our body to release energy 21% of atmosphere is oxygen Very reactive with other elements

Sodium (Na) Is a soft metal It looks very metallic and is shiny but cannot be used like your typical metal. It is too soft! A pot made of sodium cannot be used to boil water because its boiling point is lower than water (98 degrees) Sodium and water react violently to produce hydrogen gas and heat

Chlorine (Cl) Pale yellow-green gas Added to swimming pools and some water supplies to kill bacteria Chlorine can combine with Sodium to make table salt

Mercury (Hg) Metal Liquid at room temperature Extremely toxic Mercury is used to create a spark free weld when working with dangerous gases Found in older thermometers

Silver (Ag) The abundance of Silver created a ‘Silver Rush’ early in the 1800s in the Kootenays in around areas like Nelson, Kaslo, and Slocan White metallic element It is considered a precious metal It can be modeled, polished, and stretched into jewellery and silverware

Silicon (Si) Silicon is the second most common element in Earth’s crust It is not a metal but is brittle, grey, and has a metallic lustre It is used mainly as a semiconductor in electronics A semiconductor is effective at conducting electricity in controllable conditions It is found in computer chips and hardware Also used to make the frames of automobiles when combined with aluminum.