Cobalt-60 has a half life of 5.25 years. if you started with a 40 gram sample of pure cobalt-60, how many grams of cobalt-60 would remain after 10.5 years?

10 grams

Explanation:

A = A₀ (½)^(t / T)

A = 40 (½)^(10.5 / 5.25)

A = 40 (½)^2

A = 40 · ¼

A = 10

as a general rule, scissors have blades less than 6 in (15 cm) long and usually have handles with finger holes of the same size. shears have blades scissors used to cut hair or fabric must be much sharper

there is no correct list among the choices you've provided.

the list might look something like this:

-- baby human

-- piccolo

-- flute

-- soprano singer

-- trumpet

-- tenor singer

-- trombone

-- baritone singer

-- baritone horn

-- bass singer

-- tuba

since i had to make up the list myself, i made it easy on myself, and i didn't try to shuffle the string instruments and woodwinds into it too.