4.1 - What are Chemical Bonds?
What are chemicals?
Any substance that has a defined composition.
What is an ion?
An atom or molecule with an electric charge.
What is a chemical reaction?
A process where substances (reactants) transform into new, different substances (products).
What is a physical change?
A change in physical properties of a substance, such as its shape, size, or state of matter, without changing what it is MADE of.
What are reactants?
What are products?
Reactants: The starting materials introduced into a chemical reaction
Products: The material formed as a result of the chemical reaction
List FOUR chemical properties.
Could be any four of the following:
Oxidation States, Toxicity, Heat of Combustion, Reactivity, Coordination Number, Corrosivity, Chemical Bonding, Flammability
What happens in an ionic bond? What results from this?
Electrons are transferred from one atom to another.
Results in "crystal" like structures.
What are the five signs of a chemical reaction?
Color change, gas production, temperature change, formation of a precipitate, odor
A change in the chemical make-up of a substance, resulting in one or more new substances.
INCREASE
Pick ONE of the eight chemical properties and explain WHAT it is.
Answers will vary, points up to teacher discretion.
What is an example of an ionic bond?
Magnesium Oxide, Sodium Chloride (Salt), Calcium Chloride
What is synthesis?
Two or more elements or compounds combine to make a more complex substance.
Points are determined by your teacher!
To decrease the amount of kinetic energy in the molecules, should we increase or decrease the temperature?
Decrease
Why do atoms bond?
They want full outer shells, greater stability, and lower energy.
What happens in a covalent bond? What is an example?
Electrons are shared between atoms.
Examples: Water, Oxygen, Carbon Dioxide
What is decomposition?
Compounds break down into simpler substances.
What is an example of a chemical change?
Points are determined by your teacher!
Do warm/hot temperatures increase or decrease the kinetic energy in molecules?
Increase
What are the three types of chemical bonds?
Ionic, Covalent, Metallic
What is a metallic bond? What is an example?
Electrons move freely between atoms.
Examples: Copper, Iron, Aluminum, Gold
What is single replacement?
What is double replacement?
Single: Occurs when one element replaces another one in a compound
Double: Occurs when different atoms in two different compounds trade places
Can physical changes be reversed?
Can chemical changes be reversed?
YES, BY CHANGING THE CONDITIONS THAT CAUSED THE CHANGE.
(EXAMPLE: MELTING ICE CUBES)
NO, IT CANNOT BE UNDONE AND INVOLVES BREAKING/FORMING CHEMICAL BONDS
(EXAMPLE: ROTTING APPLE)
Do cool/cold temperatures increase or decrease the amount of kinetic energy in the molecules?
DECREASE