Atoms, Compounds, Mixtures, and Chemical Change

What is everything in the Universe made up of?

matter

What makes up movement in the Universe?

energy

What is energy?

capacity or power to do work

What forms can energy exist in?

• potential

• thermal

• chemical

• nuclear

What does the atomic model help us understand?

structure/interactions/properties of matter

Name this atom

Lithium Atom

What is an element?

• pure substance

• atoms are all same

What is the fundamental difference between elements?

• structure of elements

• number of protons, neutrons, and electrons

Label the following

1. Atomic Number

2. Element Symbol

3. Element Name

4. Atomic Weight

List properties of metals

• solids at room temp. (except mercury)

• conductors of heat and electricity

• generally have a high density

• lustrous

• ductile

• malleable

List properties of non-metals

• solids/gases at room temperature (except bromine)

• not conductors

• generally have a low density

• dull (not lustrous)

• brittle (crumble/break when bent)

List properties of semi-metals

• solid at room temp

• semi conductor

• usually lustrous

• usually ductile/malleable (except silicon)

Compare metals and non-metals

• metals: dense, lustrous, ductile, malleable

  non-metals: dull, brittle, low density

• metals: conductors of heat and electricity

  non-metals: not conductors

Determine whether the following elements are metals, non-metals, or semi-metals

• Lithium (Li)

• Phosphorus (P)

• Argon (Ar)

• Silicon (S)

• Scandium (Sc)

• Hydrogen (H)

• Lithium (Li) (Metal)

• Phosphorus (P) (Non-metal)

• Argon (Ar) (Non-metal)

• Silicon (S) (Semi-metal)

• Scandium (Sc) (Metal)

• Hydrogen (H) (Non-metal)

List an example for a monatomic substance, diatomic substance, polyatomic substance, and lattice.

• Monatomic - Helium

• Diatomic - Oxygen

• Polyatomic - Sulfur

• Lattice - Graphite

Compare monatomic, diatomic, and polyatomic atom arrangements,

• monatomic atom arrangement: only one atom in element

• diatomic: two atoms in one molecule of element.

• polyatomic: more than two atoms in one molecule of element

What is a compound?

• type of matter composed of different elements

• chemically bonded in fixed ratios.

Explain the differences between the elements that make up compounds and the compounds themselves.

In H2O, Hydrogen gas and Oxygen gas chemically bond to form H2O molecules, which forms liquid water. The elements that make up water have different properties compared to water.

Define an ion

• charged atom or molecule

• uneven protons:electrons

How are cations formed?

• after the atom loses electrons

How are anions formed?

• after atom gains electrons

How are ionic compounds formed?

• positively/negatively charged ions attracted to each other

Name three cations and anions

Cations: Lithium, Calcium, Magnesium

Anions: Fluorine, Chlorine, Oxygen

What is a pure substance?

• chemical composed of one type of atom/molecule/ion (can have more than one particle)

• chemically bonded to each other.

What is a mixture?

• impure substance

• particles/substances physically mixed together

• not chemically bonded

• retain their own chemical properties

Describe a heterogeneous mixture, with an example.

• molecules not mixed in even distribution

• not the same throughout

• example: muddy water.

Describe a homogeneous mixture, with an example.

• molecules mixed in even distribution

• the same throughout

• example: salt water

How is milk homogenised?

• large globules of fat form layer of cream

• broken down into smaller particles

• so tiny they stay suspended in milk

What is miscibility?

• ability for two liquid substances to be mixed together

What is immiscibility?

• liquid substances don’t mix

• form immiscible layers based on density

• example: water and oil

• oil layer formed ontop of water

What are alloys?

• homogeneous mixture of metals

• two or more metallic elements.

Name 3 alloys and describe their composition.

Steel is made of Carbon and Iron

Nichrome is mde of Nickel and Chromium

Bronze is made of Copper and Tin.

On a particle level, what are the differences between elements, compounds, and mixtures?

• elements: made up of just one type of atom

  compounds and mixtures: made up of more than one type of atom

• compounds: made up of two or more elements chemically bonded

  mixtures: elements/compounds held together by physical bonds.

What is chemical polarity in molecules?

• electron cloud of atom gains abundance of electrons in particular area

• brief negative charge on that end, and brief positive charge on opposing end

What is a solute and solvent in a solution?

• solute: dissolving solid

• liquid in which solute dissolves is solvent.

How does dissolving occur in polar and non polar solutes and solvent?

• polar solutes only dissolve in polar solvents

  non polar solutes only dissolve in non polar solvents.

• stronger attraction between solute + solvent = more soluble

• polar solute is more attracted to polar solvent as the positive and negative poles are attracted to each other

a polar solvent/solute has partial negative/positive charges, while a non polar solvent/solute is neutral throughout.

polar solvents have bonds between atoms with very different charges, while non-polar solvents have bonds between neutral atoms.

Name an example of dissolving being a physical change.

• sucrose dissolving

Name an example of dissolving being a chemical change.

• salt dissolving

• What are the differences between physical and chemical change?

• physical change: no new bonds are formed/broken

  chemical change: new bonds are formed/broken

• physical changes: easily reversed

  chemical changes: not easily reversed.

Every chemical goes through varying chemical changes based on their different chemical identities.

• What are some characteristics that indicate a chemical change has occurred?

• Change in colour

• Temperature change

• Gas is given off

• Light is produced

• A new solid is formed (precipitation

How do chemical changes relate to chemical reactions?

• chemical change occurs as a result of chemical reaction

• chemical reaction occurs → composition of chemicals change

• chemical bonds can be broken or formed

• result of a chemical reaction is a chemical change

• new chemical substance forming occurs after chemical bonds are broken/formed.

What is a reactant and product?

• reactants*: are the chemicals that are present before the chemical reaction has occurred*

• react together to form the product*: result of the chemical reaction.*

How do chemical equations represent a chemical reaction?

• chemical equation shorter/more efficient way of representing a chemical reaction

• easily understand which and how many chemicals are reacting to produce a new substance

• chemical equation shows same things as chemical reaction reactant(s) and product(s)

• in a simple equation format.

Write word equations to represent the following chemical reactions:

• Iron reacts with oxygen to produce iron oxide

• Magnesium reactions with oxygen to produce magnesium oxide

• Zinc reacts with chlorine to produce zinc chloride

• Photosynthesis reaction

• Respiration reaction

• Iron reacts with oxygen to produce iron oxide

Iron + Oxygen → Iron oxide

• Magnesium reactions with oxygen to produce magnesium oxide

Magnesium + Oxygen → Magnesium oxide

• Zinc reacts with chlorine to produce zinc chloride

Zinc + Chlorine → Zinc chloride

• Photosynthesis reaction

Carbon Dioxide + Water → Glucose + Oxygen

• Respiration reaction

Glucose + Oxygen → Carbon Dioxide + Water

List chemical equations that describe the process of chemical weathering

• CO₂ + H₂O → H₂CO₃

  Carbon Dioxide + Water → Carbonic Acid

• H₂CO₃ + CaCO₃ → Ca(HCO₃)₂

  Carbonic Acid + Calcium Carbonate → Calcium Hydrogen Carbonate