Chemistry in Context - Portable Electronics

Flashcards covering key vocabulary from the lecture notes.

Chemical Symbols

1-2 letter abbreviations for elements, often derived from Latin or Greek names

Examples of Element Symbols

Pb (lead), Hg (mercury), Cu (copper), Fe (iron), K (potassium), Sb (antimony), Ag (silver), Au (gold)

Metalloids

B, Si, Ge, As, Sb, Te, Po

Alkali Metals

Group 1

Alkaline Earth Metals

Group 2

Pnictogens

Group 15

Chalcogens

Group 16

Halogens

Group 17

Noble Gases

Group 18

Four components of matter

Solids, liquids, gases, and plasmas

Pure Substances

Elements (same type of atoms) or compounds (2 or more different types of atoms)

Mixtures

Heterogeneous (varies throughout) or homogeneous (uniform throughout)

Law of Multiple Proportions

Elements combine in integer ratios to form multiple compounds with different properties

Example of Multiple Proportions

Fe3O4 (magnetite) vs. Fe2O3 (rust)

Ions

Electrons added or subtracted from atoms

Molecules

Made up of atoms

Scales of Matter

Macroscopic (naked eye) vs. sub-microscopic/nanoscale (one-billionth of a meter)

Proton Charge/Location

+1, found in the nucleus

Neutron Charge/Location

0, found in the nucleus

Electron Charge/Location

-1, located outside the nucleus

Electrical Conductivity

Movement of electrons through a 3-D structure

Metals Isolation

Isolated from rock formations (e.g., aluminum from bauxite ore)

Significant Figures Rules

Non-zero digits, embedded zeroes, and trailing zeroes are significant; leading zeroes are not

Calculations with Sig Figs

Based on smallest # decimal places for addition/subtraction; smallest # sig figs for multiplication/division

Earth's Crust Composition

Mostly O, Si, Al, and alkali/alkaline earth metals

Oxidation

Electrons removed from a metal (M → M+ + n−)

Reduction

Electrons added to a metal/compound (M + n− → M−)

Silicon Purification Process

Si(s) + 3 HCl(g) → SiHCl3(g) + H2(g), then 2 SiHCl3(g) → Si(s) + 2 HCl(g) + SiCl4(g)

Ultra-High Purity (12N) Silicon

99.9999999999% silicon, only containing 0.0000000001% impurities

Scientific Notation

Moving decimal to the right for small numbers, left for large numbers

Computer Chip Fabrication

Silicon fabricated into cylinders (ingots) and sliced into wafers

Computer Chips

Contain billions of tiny components known as transistors

Sand

Not only used as a precursor to silicon, but also used for glassmaking

Quartz Sand

Crystalline solid (ordered 3-D structure)

Glass

Disordered solid (amorphous)

Glassmaking Process

Heated to temperatures >1000 °C and cooled rapidly

Additives in Glassmaking

Na2CO3, CaCO3, and MgCO3 used to lower the melting point

Crack-Resistant Glass

Replacing Na+ ions with larger K+ ions for added strength

Glass Strength Comparison

Normal glass withstands 7,000 psi, Gorilla glass withstands >100,000 psi

Cradle-to-Cradle Recycling

End of usefulness dovetails with the beginning of the life cycle for another product

Environmental Pillar

Pollution prevention, natural resource use

Social Pillar

Better quality of life for all members of society

Economic Pillar

Fair distribution and efficient allocation of resources

Uses for Rare Earth Metals

Vehicle catalytic converters, fluorescent lighting, memory chips, rechargeable batteries