The study of matter, its properties and its changes or transformations.
Matter is anything that has mass and takes up space.
What is a pure substance?
A pure substance is one in which all the particles that make up the substance are the same.
What is a element?
A pure substance which cannot be broken down further.
What are compounds?
Pure substances which contain two or more different elements in fixed proportion.
What is a solution?
A solution has the appearance of a compound, but actually contains two or more pure substances – ie salt dissolved in water, kool-aid in water
What is a heterogeneous mixture?
A heterogeneous mixture is where two or more pure substances are mixed together and you can still see individual particles – pizza, sand particles.
What are physical properties?
This is a characteristic of the substance – colour, hardness, odour, boiling point, melting point, etc.
What is a physical change?
A change in the size or form of a substance, which does not change the chemical properties of the substance - such as dissolving or melting.
What are chemical properties?
A characteristic behaviour that occurs when a substance is changed into a new substance
- alkali metals react violently with all halogens.
Define chemical change.
When a chemical becomes a new substance – iron rusting becoming iron oxide.
What are the two types of materials in a chemical change?
Reactants and products.
What are reactants?
The chemicals you had before the chemical change. (Chemical changes are usually called Reactions) - They are the starting materials.
What is produced by a chemical change. (The resulting materials in a chemical change.)
Define ionic bonds.
Ionic bonds are formed between a metal atom and a non-metal atom.
Define covalent bonds.
Covalent bonds are formed between non-metal atoms
Define metallic bonds.
Metallic bonds are formed between metal atoms only.
Explain what a chemical formula is.
It indicates which elements are present and the number of atoms of each element there are in the compound.
Explain how ionic compound bond.
Electrons transfer from metal to non-metal to create stable orbitals, and therefore two oppositely charged ions (electrically charged atoms) which are attracted to each other.
What is a chemical bond?
It is the force holding two or more atoms together in a structure (molecule). The atoms form them to get stability by filling their outer (valence) orbital.
What are ions?
Ions are atoms which have gained or lost electrons to become stable.
Which side of the periodic table are metals found on? Do they gain or lose electrons?
They are found on the right side of the periodic table. They tend to lose electrons.
Which side of the periodic table are non-metals found on? Do they tend to gain or lose electrons?
Non-metals tend to gain electrons and are found on the right side of the periodic table.
What are the two types of ions?
Cations and anions.
What are cations?
They are positive ions.
What are anions?
They are negatively charged ions.
How do you draw a Lewis Dot diagram?
Write the symbol for the atom, e.g. Na
Observe the number of electrons in the outer orbital of that atom.
Draw the same number of dots around the symbol as the number of electrons in the outer orbital - group them in groups of two.
What is the chemical formula for Calcium fluoride?
What is the chemical formula for Magnesium sulphide?
What are alloys?
Homogeneous mixtures containing mostly metals but sometimes non metals like carbon. When metals are mixed in different proportion their physical properties can change dramatically. (Iron with different amounts of carbon mixed in can be flexible, springy or brittle.)
What are 4 properties of the Alkali Metals?
React violently with water or halogens
These elements lose one electron when they react
They react very easily
They are poisonus, but necessary to life.
They are solid at room temp, malleable, shiny, conductive, ductile, etc.
Which group on the periodic table reacts violently with halogens?
Alkali Metals react violently with them.
What are 4 properties of Alkaline Earth Metals?
React with water and halogens
Lose electrons when they react (forming cations)
Poisonus, but needed for life.
Solid at room temp, malleable, shiny, ductile, conductive, etc.
Name 3 properties of halogens.
All are poisonus.
Found at room temp as solids, liquids, or gases.
Gain electrons forming anions when they react.
What are some signs of a chemical change?
New chemical (solid) forms
Starting chemical disappears.
What state are ionic compounds found in at room temperature? Molecular compounds?
Ionic are solids always, Molecular can be solid, liquid or gas depending on molecule size.
Do ionic compounds have odour? molecular compounds?
Ionic don't have this, molecular do.
Are ionic compounds solluble in water? Molecular compounds?
Ionic are, molecular are not usually.
Are ionic compounds solluble in organic solvent? molecular compounds?
Ionic aren't, molecular are.
Are ionic compounds conductive in water? Molecular compounds?
Ionic are, molecular aren't.
How hard are ionic compounds? Molecular compounds?
Ionic compounds are hard, molecular compounds typically aren't.
A ______________ is a pure substance which is made of two or more elements bonded in fixed proportion.
2. If one substance can dissolve into another it is considered ______________________.
3. ______________ mixtures (solutions) look like pure substances but aren't.
4. A ______________ ______________ can only be seen when a chemical change takes place.
5. A substance can exist as solids, liquids or gases. These are called the _____________ of matter.
6. You have a material in which you can see particles of various colours and shapes. This is a ___________________________ mixture.
7. An _________ is an atom which has lost or gained electrons.
8. ________________ are negatively charged ions.
9. An ionic ____________ is caused when a negative ion and a positive ion are attracted. They form strong bonds.
10. A ___________________ ion is one that has more than one atom present in its makeup.
11. ___________________ or _________________________ compounds share electrons between non-metals, and have weak bonds and can readily combine with other atoms when reacting.
molecular , covalent
____________ _______________ contain only one kind of particle. ________________ contain combinations of different particles in no fixed proportion.
physical properties mixtures pure substances elements compounds heterogeneous homogeneous chemical ions
pure substances , mixtures
_______________________ are pure substances which appear on the periodic table, _______________ are combinations of bonded elements in fixed proportion.
elements , compounds
3. __________________ properties are ones which you can detect with your 5 senses such as colour or hardness.
4. Atoms which have lost or gained electrons are called ________________.
1. ___________________ are chemicals you start with before a reaction, ____________________ are the chemicals you end up with after the reaction.
2. A(n) _____________ equation uses the names of chemicals to describe what is happening in a reaction.
3. A(n) _________________ equation has all the formulas for the chemicals in a reaction, but the numbers of atoms on either side are not the same.
4. ____________________ are sour tasting chemicals that are water soluble and release H+ ions. ________________ are bitter tasting chemicals that are soluble in water and slippery to the touch. They usually but do not necessarily have ______________ ions.
Acids Bases OH-
5. A(n) _________________________ is a chemical which changes colour when it is exposed to either an acid or a base.
6. A(n) ____________________________ reaction is one where there are equal amounts of acid and base added together to create water and a ______________________.
7. The ____________ scale can be used to show how acidic or basic a substance is. Acidic substances have a _____________ pH number, while basic substances have a ______________ pH number.
pH low high
8. A __________________ is a neutralization reaction used to determine how much acid or base is in an unknown sample.