ca
ca — noun
1. a short written form for the US state of California, used in postal addresses an
a short written form for the US state of California, used in postal addresses and on forms after the name of a city.
Please send the form to 742 Maple Street, San Diego, CA 92101.
postal address format: city, CA ZIP
Asher moved from Chicago to Los Angeles, CA, to join a film production company.
The online form asked for her city and state, so she typed "San Francisco, CA."
Benjamin's return address showed a small town in northern CA, about an hour from the coast.
When mailing documents to the Sacramento office, always put "CA" after the city name and before the ZIP code.
- Calif.
An older written abbreviation; CA is now the standard USPS form.
用法筆記
Always written in capital letters without a period. This abbreviation is standard in US postal addresses and on official forms, but in general writing the full name 'California' is preferred.
常見錯誤
ca — noun
1. the chemical symbol for calcium, a soft silver-white metal that is an important
the chemical symbol for calcium, a soft silver-white metal that is an important element for living things, shown on the periodic table with the atomic number 20.
The periodic table shows Ca between potassium and scandium.
position in periodic table
Aoi's lab report identified CaCO₃ as the main compound found in limestone.
Ca in chemical formulas
The nutrition label on the milk carton listed the calcium content as "Ca 300 mg" per serving.
In the chemistry exam, students had to name the element represented by the symbol Ca.
Mateo learned that the human body needs Ca to build strong bones and teeth.
- calcium
The full name of the element; Ca is the written symbol used in formulas and tables.
用法筆記
The symbol is written with a capital C and a lowercase a (Ca). It is never written as all capitals (CA) or all lowercase (ca), which would be confused with the state abbreviation.