Semester 1 Final Exam Review Notes

Determining an Element
- Element is identified by the number of protons, which corresponds to atomic number.
Determining a Compound
- A compound is combination of different elements that are chemically bonded together
Heterogeneous Mixtures
- A heterogeneous mixture is a visibly different substances or phases. components can be physically separated and visually identified.
Homogeneous Mixtures
- A homogeneous mixture has uniform composition, meaning the individual components are not visibly distinct and can often only be separated by chemical means.
Classification Examples
- Magnesium Fluoride (MgF2): Compound (C)
- Carbon (C): Element (E)
- Chex Mix: Heterogeneous Mixture (HTM)
- Lemonade powder in water: Homogeneous Mixture (HM)

Object Behavior in Liquid
- If an object has a density less than 1 g/mL, it will float, greater than 1 g/mL, object will sink

Parts of the Atom Table

Name	Location	Charge	Affects Name	Affects Charge	Affects Mass
Proton	Inside nucleus	+1	Yes	Yes	Yes
Neutron	Inside nucleus	0	No	No	Yes
Electron	Outside nucleus	-1	No	Yes	No

Charge Relationships
- Neutral atoms have an equal number of protons and electrons.
- Positive ions have more protons than electrons.
- Negative ions have more electrons than protons.

Relationship Between Distance and Attractive Force
- As distance between charged particles increases, attractive force decreases.
Relationship Between Number of Protons and Attractive Force
- If distance remains constant, attractive force increases with increase in the number of protons.
Distance Change in Model 2
- As the outermost electron's distance from the nucleus increases, the attractive force decreases, particularly down a group in the periodic table.
Changes in Attractive Force Explained by Protons
- Changes in attractive force can be explained by the number of protons in the nucleus; as the number of protons increases (while distance is constant), the attractive force also increases.

True or False Statements
- Metals are shiny: True
- Nonmetals are shiny: False
- Metals are not reactive: False
- Nonmetals are reactive: True
- Metals are typically solid: True
- Nonmetals can be solids, liquids, or gases: True
- Metals are high electrical conductors: True
- Nonmetals are high electrical conductors: False
- Metals have a low melting point: False
- Nonmetals have a low melting point: True
- Metals gain electrons: False
- Nonmetals gain electrons: True

Sublevel Electron Capacities
- s block = 2 electrons
- p block = 6 electrons
- d block = 10 electrons
- f block = 14 electrons

Types of Ions
- A positive ion is a cation.
- A negative ion is a anion.
Ion Charge Determination
- Ion charge depends on the gain or loss of electrons:
  - If an electron is lost by a metal, the ion gains a positive charge (cation).
  - If an electron is gained by a non-metal, the ion gains a negative charge (anion).

Definition of Isotope
- An isotope is defined as nuclei of the same element that possess different numbers of neutrons (resulting in different atomic masses).
Properties of Isotopes
- Given an atomic symbol with various properties:
  - Atomic Number: Total number of protons in nucleus.
  - Number of Protons: Equals atomic number.
  - Number of Neutrons: Atomic Mass - Atomic Number.
  - Number of Electrons: Equals number of protons in a neutral atom.
  - Example: For atomic number 4 (Beryllium): 4 protons, 4 electrons, isotopes may vary in neutrons.

Conversions
- For a 10-kilometer race, convert kilometers to miles:
  - 0.621 miles = 1.00 km

Specific Heat Capacity Question
- When salt is added to ice on the sidewalk, the temperature of the area typically decreases as the melting ice absorbs heat from the surroundings.
Heat Transfer Principle
- Heat moves from the hotter object to the colder object, as heat always flows along the temperature gradient from high to low.