Scimatics 8HBuilding Blocks of Matter

Elementary particles: particles that cannot be split apart into smaller particles ex. quarks and leptons

Quarks: elementary particles that make up neutrons and protonso Six different types called flavours

Proton: 2 up quarks Neutron:1 up quark,and 1 down quark and2 down quarks

Leptons: electrons are a type of lepton. There are six flavours of leptons

Elementary particles < subatomic particles < atom < element < compound < pure substance < mixture < matter

Pure Substances: A pure substance is a substance that is made up of only one type of matter. Examples: gold, water, and oxygen Two kinds of pure substances are elements and compounds

o i) Elements: An element is a pure substance that can’t be broken down or separated into simpler substances.

By studying elements, we can learn more about the structure of matter Elements are made of only one kind of atom. There are over 115 different elements. 92 occur naturally, the rest are man made (synthetic). Chemists use internationally recognized symbols for each element.

o ii) Compound: A compound is a pure substance that results from a combining two or more different chemical elements.

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Key VocabularySubatomic particles Element MixtureElementary particles Compound HeterogeneousQuarks Pure Substance HomogenousLeptons

Scimatics 8H The atoms of the different elements are held together by chemical bonds that

are difficult to break by physical means They can be broken down into elements by chemical means. Example: Water is made up of the elements hydrogen and oxygen.

Mixtures: A mixture is a blend of two or more pure substances n which each substance retains its individual properties.

Can be separated by physical means Two types of mixtures are:

o i) Homogenous mixtures Referred to as a solution. Mixed uniformly throughout and you cannot see their components (even with

a microscope!)o ii) Heterogenous mixtures

mixture made up of two or more substances that you can visually distinguish Ex: rocks, granola bar

The Periodic TableChemical Symbols

Chemical symbols consist of the first letter from the Greek or Latin word capitalized (e.g. carbon = C, Carbo is Latin for coal).

The first letter capitalized plus a second letter lower case (non-capitalized) (e.g. lead = Pb, Plumbum is Latin for lead)

3 letters means that the element doesn’t have an ͞official name ͟ yet, it’s a temporary name

Reading the Periodic Table:Element’s Name: The element’s name is located in the middle of

the left hand side.

Symbol: Each element is represented by a one or two letter symbol. (three letter symbols means that there isn’t a ͞proper͟ name for it yet)

Atomic Number: The atomic number is located at the top on left hand side and is the number of protons in the nucleus.As you go from left to right, the atomic number goes up by 1 every time

Atomic Mass: Atomic mass is located at the bottom of the left hand side and is the mass of an average atom of an element (measured in amu’s) atomic mass unit. As you go from left to right the atomic mass usually increases but there are a few exceptions

Ion Charge: The ion charge(s) is the electric charge that forms when it gains or loses electrons. Some elements will have a multiple ion charge & it’s called a multivalent element.

Organizing the Periodic Table:

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Scimatics 8HElements can be organized by their properties. Dmitri Mendeleev created the first periodic table in 1867. He arranged the elements according to their properties and had left room for elements that hadn’t yet been discovered.

Period: Each horizontal row in the periodic table. Beginning with hydrogen in the first period, there are7 periods in total

Family or Group: -Each verticle column in the periodic table. Groups are numbered from 1-18.These elements share similar physical and chemical properties. Four well known groups are the alkali metals, alkaline earth metals, halogens and noble gases.

Elements are classified as metals, non-metals and semi-metals.Through organization due to properties, we see three main groups within the periodic table; metals, non metals and metalloids (semi- metals).

Table 1: Properties of Metals, Non Metals and Metalloids

* Refer to this table for properties of the three groups

Metals- Most elements are metals. Except for mercury, metals are solid at room temperature, they are very hard and are often silver/grey in colour.

Types of metals:

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Malleable: capable of being beaten into thin sheets)

Ductile (capable of being pulled into wires)

Scimatics 8H Alkali metals - Group 1 (excluding hydrogen)

o highly reactive. Reactivity increases as you go down the groupo Have low melting points ( below 2000C) and are typically soft and solids.

Alkaline earth metal - Group 2o very reactive but less so than the alkali metals

Non-metals- Found on the upper right side of periodic table. Typical properties are that they are the opposite of metal properties (e.g. NOT malleable, NOT shiny, poor conductor) and are usually found as gases. If they are solid, they are usually brittle. Hydrogen: usually placed on the left side of periodic table but is a non-metal.

Types of non metals: Halogens - Group 17

o highly reactiveo an odd group as at room temperature they are found in a variety of different states

of matter.

Noble Gases - Group18o most stable and unreactiveo at room temperature, they are colourless, odourless gas

Semi-metals -Sometimes referred to as metalloids. They are ‘in between elements’, these elements share some physical and chemical properties with metals and non-metals. Semi-metals are shiny solids at room temperature but are brittle, and not ductile like true metals. Ex. Silicon used in many electronics such as computers, ipads, cellphones, appliances.

Practice Questions:

1.List three pieces of information besides an element’s name and symbol that are recorded on a periodic table.2. State how many protons are present in each of the following atoms:

a) silicon b) chromium c) iodine3. List the following elements by atomic mass from lightest to heaviest:

zinc, calcium, cobalt, nickel, carbon. Write the atomic mass beside each one.4. Where on the periodic table do you find the a) metals b) non metals c) metalloids?

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