Use numerals with units of time or measure, and use a space between the numeral and the unit, except%and ◦ (angular degrees). e.g. 15 d, 9 h, 6 min, 25 mL, 0.30 g, 180◦C, but 50% and 180◦C, and
for all numbers greater than ten. With items other than units of time
or measure, use words for cardinal numbers less than 10, use numerals
for 10 and above. Spell out ordinals “first” through “ninth”,
use numerals for 10th or greater. e.g. three flasks, 30 flasks, third
flask, 12th flask, seven trees, and 10 trees. The exception is to use
all numerals in a series or range containing numbers 10 or greater, even
in non-technical text, e.g. 5, 8, and 12 experiments, 2nd and 20th
samples, 5-15 repetitions.While beginning a sentence the numbers should
be spelt out. When describing the units in a series of numbers, the use
of the omitted form is preferred, only the last needs to be kept, for
example 20, 40, and 60 mg/L (not 20 mg/L, 40 mg/L, and 60 mg/L); 20-60
mg/g (not 20 mg/g-60 mg/g), but the numberical percentage should be in
full form, for example, 20%–60% (not 20–60%). The measured data should
be consistent with the accuracy of the measuring instrument.
3.4. Abbreviations
Only
standard abbreviations, as listed in The ACS Style Guide may be used
without definition. Terms appearing frequently within a paper may be
abbreviated, but should be spelled out at first citation, with the
abbreviation following in parentheses. Examples: pharmacokinetics (PK),