Lab Safety and Measurement Quiz

Lab Safety and Measurement

• Safety Procedures: Know proper procedures for smelling chemicals, chemical disposal, broken glassware, and appropriate lab attire. Be prepared to answer true/false questions about lab safety.
• Physical vs. Chemical Changes: Distinguish between physical and chemical changes, identifying each type in given scenarios. Be able to identify physical or chemical changes in various situations.
• Bath Bomb Experiment: Classify the bath bomb experiment as either a physical or chemical change and explain the reasoning.
• Scientific Notation: Express 345,000,000 in scientific notation. (3.45 x 10⁸)
• Standard Notation: Write 3.4 x 10^-5 in standard notation. (0.000034)
• Temperature Conversions: Convert 35°C to Fahrenheit and 13°F to Kelvin. (95°F, 256 K approximately)
• Metric Conversions: Convert 24 liters to deciliters, 5 kilograms to grams, and 310 millimeters to centimeters. (240 dL, 5000 g, 31 cm)
• Conversion Factors: Convert 13 inches to miles and 1 kilometer to feet using conversion factors.
• States of Matter: Draw and label the four states of matter (solid, liquid, gas, plasma).
• Kinetic Energy and States of Matter: Illustrate the trend of increasing kinetic energy across the states of matter with an arrow. (Arrow should point from solid, to liquid, to gas, and then plasma)
• Solutions: Define/label solution, solvent, solute and identify whether a given solution is homogeneous or heterogeneous.
• Experimental Design: Analyze experimental designs to identify independent variable (IV), dependent variable (DV), control group, experimental groups, constants, and appropriate graph types (bar, line, circle). Be prepared to identify these components in experimental designs.
• Graph Axis: Determine which variable goes on the x-axis and y-axis for experimental design graphs.
• Density Calculations: Solve density problems using the formula D = m/v, calculating any missing variable.
• Water Displacement: Explain the concept of water displacement in density determination. Water displacement measures the volume of an object by measuring the change in water level.

Atomic Structure

• Periodic Table Information: Determine atomic number, number of protons, electrons, neutrons, and atomic mass from the periodic table for various elements. Be prepared to fill out tables with missing information.
• Atomic Components: Name and describe the parts of an atom (protons, neutrons, electrons), including their charges. Protons (+), neutrons (neutral), and electrons (-).
• Atomic Structure Forces: Explain the forces holding an atom together. Electrostatic forces (protons attracting electrons) and the strong nuclear force between protons and neutrons.
• Element Identification: Explain how the atomic structure determines the identity of an element. The number of protons defines an element.
• Nucleus vs. Electron Cloud: Differentiate between the nucleus and electron cloud of an atom. Nucleus is compact and dense, containing protons and neutrons. Electron cloud is a region where electrons are located.
• Bohr Models: Draw Bohr model diagrams for specific elements (e.g., sodium).
• Lewis Dot Structures: Draw Lewis dot structures for given elements (e.g., calcium).
• Valence Electrons: Compare and contrast the valence electrons of sodium, chlorine, and argon, explaining the relationship to reactivity. Valence electrons are the outermost electrons that determine bonding and reactivity.
• Metal/Nonmetal/Metalloid Identification: Identify elements as metals, nonmetals, or metalloids based on their position on the periodic table (e.g., aluminum, potassium, sulfur, argon).
• Ions, Cations, Anions: Define ions, cations, and anions. Ions are charged atoms. Cations are positively charged ions. Anions are negatively charged ions.
• Halogens vs. Alkali Metals: Determine whether halogens or alkali metals are more likely to form anions or cations to become more stable. Halogens form anions, alkali metals form cations to achieve stable electron configurations.
• Valence Electrons from Periodic Table: Determine the number of valence electrons for specified elements (e.g., boron, strontium, carbon, selenium) using the periodic table.
• Isotopes: Define isotopes. Atoms of the same element that have different numbers of neutrons.
• Atomic Mass vs. Mass Number: Differentiate between atomic mass and mass number and the information each provides. Atomic mass is an average mass, while mass number is the sum of protons and neutrons in a specific isotope, a whole number.

Electrons

• Electron Behavior: Describe how electrons behave. Electrons exhibit wave-particle duality and are located in regions of probability called electron clouds.
• Element Stability: Explain how an element's stability correlates to its valence electron configuration (e.g., sodium, neon). Elements tend to gain or lose electrons to achieve stable noble gas configurations (full valence shells).
• Electron Configurations: Analyze electron configurations (e.g., 1s² 2s² 2p⁶ 3s¹ 3p³) to determine element, number of electrons, valence electrons, and energy levels.
• Electron Configuration Writing: Write electron configurations for elements with atomic numbers 50 or lower.
• Electromagnetic Spectrum: Analyze electromagnetic spectra, relating wavelength, frequency, and energy. Higher frequency = higher energy and shorter wavelength.
• Frequency and Wavelength: Describe the relationship between frequency decrease and wavelength changes in light. Inverse relationship; as one decreases, the other increases.
• Frequency and Energy: Describe the relationship between frequency decrease and energy changes in light. Inverse relationship.
• Ionic Radius Trends: Describe how ionic radius changes for elements that gain or lose electrons. Trend: lost electrons tend to shrink ionic radius, while gained electrons tend to increase the radius.
• Electronegativity Comparison: Compare electronegativities of different elements or groups (e.g., halogens vs. alkali metals, alkaline earth metals vs. alkali metals). Trend: electronegativity generally increases across a period and decreases down a group.
• Metal Reactivity Trend: Describe the trend in metal reactivity on the periodic table. Trend: reactivity decreases across a period and increases down a group.
• Nonmetal Reactivity Trend: Describe the trend in nonmetal reactivity on the periodic table. Trend: reactivity increases across a period and decreases down a group.
• Bond Types and Electronegativity: Determine if a bond between two given elements is covalent, polar covalent, or ionic based on electronegativity differences. Significant difference indicates ionic bond.
• Ionization Energy Comparison: Compare ionization energies of different elements (e.g., Rb, K, Al, Cl), identifying those with higher or lower values. Trend: ionization energy generally decreases down a group and increases across a period.

Additional Concepts

• Forces within vs. between substances: Forces within a substance relate to internal structure (intramolecular forces); forces between substances relate to attraction between multiple substances (intermolecular forces).

• Bonding as a spectrum: Bonding exists on a spectrum, varying from purely ionic to purely covalent, with many intermediate polar covalent bonds.

• Chemical bonds, reactions, and compounds: Chemical bonds form compounds, which undergo chemical reactions.

• Atom bonding motivations: Atoms form bonds to achieve a stable electron configuration, usually like the noble gases, thus gaining a full valence shell. Some atoms like noble gases are stable on their own.

• Chemical formulas for ionic vs. covalent compounds: Ionic formulas show the simplest ratio of ions. Covalent formulas show the exact number of atoms in a molecule.

• Covalent vs. Ionic Bonds: (A table distinguishing covalent and ionic bonds is requested but not provided in the initial text)

• Covalent vs. Ionic Compounds: (A table distinguishing properties of covalent and ionic compounds is requested but not provided in the initial text)

• Chemical Formula Information and Prediction: Chemical formulas provide element ratio and predict compound properties based on bonding types and electronegativity.

• Bond/compound identification (ionic/covalent): Identify bonding type by electronegativity difference, structure, or example. Use periodic table to predict oxidation states and bonding tendencies.

• Practice: List the number of atoms of each element in the compounds below:

• a. AlF₃ (1 Al, 3 F)

• b. K₃P (3 K, 1 P)

• c. Ca(ClO₃)₂ (1 Ca, 6 Cl, 18 O)