4.1 Elements and Symbols Study Notes

4.1 Elements and Symbols

  • All matter is composed of elements. There are 118118 different kinds of elements, of which 8888 occur naturally in the world. Examples of everyday elements:

    • Aluminum in foil

    • Gold, silver, or platinum in jewelry

    • Titanium or carbon in sports equipment (rackets, clubs)

    • Calcium and phosphorus form the structure of bones and teeth

    • Iron and copper are involved in red blood cell formation

    • Iodine is required for thyroid function

  • Elements are pure substances that cannot be broken down into simpler substances.

  • Names of elements have origins in various sources (planets, mythological figures, colors, minerals, geographic locations, famous people). A list of sources is given in Table 4.1. A complete list of elements and their symbols is found on the inside front cover of this text.

  • 88 natural elements exist; there are 118118 total elements (and thus 11888=30118-88=30 synthetic/man-made elements).


Symbols: Formation and Writing Rules

  • Chemical symbols are one- or two-letter abbreviations for element names.

  • Capitalization rule: Only the first letter is capitalized. If there is a second letter, it is lowercase. This helps distinguish elements (e.g., Co for cobalt) from two-letter sequences that could be read as two elements if both letters were capitalized (e.g., CO would mean carbon and oxygen, not cobalt).

  • Two capital letters (e.g., COCO) would indicate two different elements (C and O).

  • Some symbols come from modern names; some come from ancient/Latin names:

    • Na comes from natrium (Latin for sodium)

    • Fe comes from ferrum (Latin for iron)

  • Example: cobalt has the symbol Co; two-letter symbol CO would be interpreted as two elements (C and O) rather than cobalt.

  • The periodic table provides a standard set of symbols for the elements. The symbol is used internationally to represent the element in chemical formulas and reactions.

  • Summary statistics: 118118 total elements, of which 8888 are natural and 3030 are synthetic.


Source of Names (Table 4.1) – Selected Examples

  • Uranium (U) – Named after the planet Uranus.

  • Titanium (Ti) – Named after the Titans (mythology).

  • Chlorine (Cl) – From Chloros: “greenish yellow” (Greek).

  • Iodine (I) – From Ioeides: “violet” (Greek).

  • Magnesium (Mg) – From Magnesia, a mineral.

  • Tennessine (Ts) – Named after Tennessee.

  • Curium (Cm) – Named for Marie and Pierre Curie.

  • Copernicium (Cn) – Named for Nicolaus Copernicus.

  • Aluminum (Al) – symbol Al; origin linked to aluminum naming conventions.

  • Note: The complete list of names and symbols is provided in Table 4.2 (and earlier in Table 4.1 for origins of names).


Names and Symbols of Some Common Elements (Table 4.2)

  • Aluminum – Al

  • Argon – Ar

  • Arsenic – As

  • Barium – Ba

  • Boron – B

  • Bromine – Br

  • Cadmium – Cd

  • Calcium – Ca

  • Carbon – C

  • Chlorine – Cl

  • Chromium – Cr

  • Cobalt – Co

  • Copper (cuprum) – Cu

  • Fluorine – F

  • Gallium – Ga

  • Gold (aurum) – Au

  • Helium – He

  • Hydrogen – H

  • Iodine – I

  • Iron (ferrum) – Fe

  • Lead (plumbum) – Pb

  • Lithium – Li

  • Magnesium – Mg

  • Manganese – Mn

  • Mercury (hydrargyrum) – Hg

  • Neon – Ne

  • Nickel – Ni

  • Nitrogen – N

  • Oxygen – O

  • Phosphorus – P

  • Platinum – Pt

  • Potassium (kalium) – K

  • Radium – Ra

  • Silicon – Si

  • Silver (argentum) – Ag

  • Sodium (natrium) – Na

  • Strontium – Sr

  • Sulfur – S

  • Tin (stannum) – Sn

  • Titanium – Ti

  • Seaborgium – Sg (example; listed in practice problems)

  • Quick tip: Some symbols reflect historical/Latin names (e.g., Na from natrium; Fe from ferrum). Some reflect modern naming, some honor scientists, etc.


Quick Practice: Symbols and Names (Worked Examples)

4.1 Practice Problems: Write the symbols for the following elements

  • a. copper → Cu

  • b. platinum → Pt

  • c. calcium → Ca

  • d. manganese → Mn

  • e. iron → Fe

  • f. barium → Ba

  • g. lead → Pb

  • h. strontium → Sr

4.2 Practice Problems: Write the symbols for the following elements

  • a. oxygen → O

  • b. lithium → Li

  • c. uranium → U

  • d. titanium → Ti

4.3 Clinical Applications: Write the name for the symbol of each of the following elements found in the body

  • a. C → Carbon

  • b. Cl → Chlorine

  • c. I → Iodine

  • d. Se → Selenium

  • e. N → Nitrogen

  • f. S → Sulfur

  • g. Zn → Zinc

  • h. Co → Cobalt

4.4 Write the name for the symbol of each of the following elements found in the body

  • a. V → Vanadium

4.5 Elements in common medicinal formulas (name the elements in the formulas)

  • a. table salt, NaCl → Sodium, Chlorine

  • b. plaster casts, CaSO$_4$ → Calcium, Sulfur, Oxygen

  • c. Demerol (meperidine) formula → Carbon, Hydrogen, Nitrogen, Oxygen

  • d. treatment of bipolar disorder (lithium-containing) → Lithium, Carbon, Oxygen

4.6 Elements in medicinal formulas (name the elements in the formulas)

  • a. salt substitute, KCl → Potassium, Chlorine

  • b. dental cement (commonly zinc phosphate cement, Zn$3$(PO$4$)$_2$) → Zinc, Phosphorus, Oxygen

  • c. antacid (commonly aluminum hydroxide, Al(OH)$_3$) → Aluminum, Oxygen, Hydrogen

  • d. contrast agent for X-ray (barium sulfate, BaSO$_4$) → Barium, Sulfur, Oxygen


Quick reference notes:

  • Symbols are written with a capital first letter and a lowercase second letter if present: e.g., extNa,extFe,extCoext{Na}, ext{Fe}, ext{Co}. A two-capital sequence like extCOext{CO} would mean two elements (C and O) rather than cobalt.

  • For common compounds mentioned here, use the element names: NaCl (sodium chloride), CaSO$4$ (calcium sulfate), BaSO$4$ (barium sulfate), Al(OH)$3$ (aluminum hydroxide), KCl (potassium chloride), Zn$3$(PO$4$)$2$ (zinc phosphate), Li$2$CO$3$ (lithium carbonate).

  • Important origins: Na from natrium, Fe from ferrum, Ti from Titan; others follow planetary, geographic, or mythological sources as noted in Table 4.1.


Note: The content above mirrors the key ideas and exemplars shown in the transcript for 4.1 Elements and Symbols, including symbols, naming origins, and common element lists (Tables 4.1 and 4.2), plus representative practice problems and solutions intended to support exam preparation.