Unit 0: Lab Safety & Matter Classification
Definition: Matter made of only one type of atom and found directly on the periodic table
What is an Element?
Location & Charge: The subatomic particle found in the nucleus and possessing a positive (+) charge.
What is a Proton (p+)?
Definition: A substance's ability to change into a new substance; examples include flammability and reactivity.
What is a Chemical Property?
Flame Test "Why": When electrons fall back down to a lower, more stable energy level, they release the absorbed energy as this.
What is Light (or photons)?
State of Matter: This state of matter has a definite volume but an indefinite shape.
What is a Liquid?
Safety Rule: The action you should take immediately if you get a chemical in your eye
What is Go to the Eyewash Station and flush for a minimum of 15 minutes?
Calculation Rule: For a neutral atom, the number of electrons is equal to the number of this subatomic particle.
What are Protons (or the Atomic Number)?
Trend Down: The trend for Atomic Radius as you move down a group on the periodic table.
What is Increases (Gets Bigger)?
Metal Reactivity "Why": Down a group, the electron is farther away due to more electron shells, which weakens the nuclear pull and lowers this energy.
What is Ionization Energy?
Classification: Tearing a piece of paper or dissolving sugar in water are examples of this type of change.
What is a Physical Change?
Definition: A type of change that alters the form or state of a substance, like melting or freezing, but not its chemical formula.
What is a Physical Change (P)?
Scientist: He is credited with the discovery of the Electron (e−) and the Plum Pudding Model.
Who is Thomson?
Rule: The principle stating that electrons fill the lowest energy level first.
What is the Aufbau Principle?
DOUBLE JEOPARDY (600 pts): Using the concepts of Atomic Radius and Ionization Energy, explain why Cesium (Cs) is significantly more reactive than Lithium (Li).
What is the fact that Cesium has more electron shells (larger radius), which leads to a weaker nuclear pull, resulting in a lower Ionization Energy and making it easier to lose its valence electron?
Property Type: The ability of a compound to undergo oxidation or the ability to burn (flammability).
What is a Chemical Property (C)?
Key Clue: This classification of matter is identifiable by a formula with two or more different capital letters.
What is a Compound?
Model & Discovery: This scientist discovered the small, dense, positive Nucleus and concluded the atom is mostly empty space.
Who is Rutherford?
Rule: The rule that states within a sublevel (like p or d), electrons fill each orbital singly before pairing up.
What is Hund's Rule?
Atomic Radius "Why": As you move across a period, this force/charge increases, pulling the electrons closer to the nucleus and making the atom smaller.
What is the Nuclear Charge (or number of protons)?
State of Matter: The state where particles are far apart and move very quickly, resulting in an indefinite volume and indefinite shape.
What is a Gas?
DOUBLE JEOPARDY (1000 pts): Write the full electron configuration for a neutral atom of Magnesium (Mg).
What is 1s22s22p63s2
Particle & Rule: This neutral subatomic particle is calculated by subtracting the Atomic Number from the Mass Number.
What is a Neutron?
Trend Across: The trend for Ionization Energy (the energy to lose an electron) as you move across a period (left to right).
What is Increases (Harder to lose an e−)?
Ionization Energy "Why": Moving across a period, it becomes harder to lose an electron because the increased nuclear charge creates a stronger pull on the valence electrons.
What is because the Increased number of protons (nuclear charge) creates a stronger attraction to the valence electrons?
Property Type: Density, Color, and Boiling Point are all examples of this quality that can be observed or measured without changing the substance.
What is a Physical Property (P)?