A typical atom has a diameter of about 1.0×10−10m. Approximately how many atoms are there along a 2.0 −cm line?
Express your answer using two significant figures.

10m

Explanation:

if it was at the 2.0 line it would be 10 m

the device is called “ rocket engine”

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.